diff --git a/extras/Introjucer/Source/Application/jucer_AppearanceSettings.cpp b/extras/Introjucer/Source/Application/jucer_AppearanceSettings.cpp
index f2ed9902cb..f462fdc6ba 100644
--- a/extras/Introjucer/Source/Application/jucer_AppearanceSettings.cpp
+++ b/extras/Introjucer/Source/Application/jucer_AppearanceSettings.cpp
@@ -537,7 +537,7 @@ IntrojucerLookAndFeel::IntrojucerLookAndFeel()
                getScrollbarColourForBackground (findColour (mainBackgroundColourId)));
 }
 
-Colour IntrojucerLookAndFeel::getScrollbarColourForBackground (const Colour& background)
+Colour IntrojucerLookAndFeel::getScrollbarColourForBackground (Colour background)
 {
     return background.contrasting().withAlpha (0.13f);
 }
diff --git a/extras/Introjucer/Source/Application/jucer_AppearanceSettings.h b/extras/Introjucer/Source/Application/jucer_AppearanceSettings.h
index 6bc641d1ab..378cd96db2 100644
--- a/extras/Introjucer/Source/Application/jucer_AppearanceSettings.h
+++ b/extras/Introjucer/Source/Application/jucer_AppearanceSettings.h
@@ -110,7 +110,7 @@ public:
     void drawButtonBackground (Graphics& g, Button& button, const Colour& backgroundColour,
                                bool isMouseOverButton, bool isButtonDown);
 
-    static Colour getScrollbarColourForBackground (const Colour& background);
+    static Colour getScrollbarColourForBackground (Colour background);
 
 private:
     Image backgroundTexture;
diff --git a/extras/Introjucer/Source/ComponentEditor/properties/jucer_ComponentColourProperty.h b/extras/Introjucer/Source/ComponentEditor/properties/jucer_ComponentColourProperty.h
index 3ecb4dda9f..74ec2dea3b 100644
--- a/extras/Introjucer/Source/ComponentEditor/properties/jucer_ComponentColourProperty.h
+++ b/extras/Introjucer/Source/ComponentEditor/properties/jucer_ComponentColourProperty.h
@@ -80,10 +80,6 @@ public:
     {
     }
 
-    ~ComponentColourIdProperty()
-    {
-    }
-
     //==============================================================================
     Colour getColour() const
     {
diff --git a/extras/Introjucer/Source/Utility/jucer_CodeHelpers.cpp b/extras/Introjucer/Source/Utility/jucer_CodeHelpers.cpp
index 3610f0bfe7..078e75de61 100644
--- a/extras/Introjucer/Source/Utility/jucer_CodeHelpers.cpp
+++ b/extras/Introjucer/Source/Utility/jucer_CodeHelpers.cpp
@@ -283,7 +283,7 @@ namespace CodeHelpers
         return value ? "true" : "false";
     }
 
-    String colourToCode (const Colour& col)
+    String colourToCode (Colour col)
     {
         const Colour colours[] =
         {
diff --git a/extras/Introjucer/Source/Utility/jucer_CodeHelpers.h b/extras/Introjucer/Source/Utility/jucer_CodeHelpers.h
index 44891f91a1..c3f9df0ddb 100644
--- a/extras/Introjucer/Source/Utility/jucer_CodeHelpers.h
+++ b/extras/Introjucer/Source/Utility/jucer_CodeHelpers.h
@@ -41,7 +41,7 @@ namespace CodeHelpers
     String floatLiteral (double value, int numDecPlaces);
     String boolLiteral (bool value);
 
-    String colourToCode (const Colour& col);
+    String colourToCode (Colour col);
     String justificationToCode (const Justification&);
 
     String alignFunctionCallParams (const String& call, const StringArray& parameters, int maxLineLength);
diff --git a/modules/juce_audio_plugin_client/Standalone/juce_StandaloneFilterWindow.h b/modules/juce_audio_plugin_client/Standalone/juce_StandaloneFilterWindow.h
index e1dfad5501..cde253e53d 100644
--- a/modules/juce_audio_plugin_client/Standalone/juce_StandaloneFilterWindow.h
+++ b/modules/juce_audio_plugin_client/Standalone/juce_StandaloneFilterWindow.h
@@ -46,7 +46,7 @@ public:
         class and deleted automatically when no longer needed. (It can also be null)
     */
     StandaloneFilterWindow (const String& title,
-                            const Colour& backgroundColour,
+                            Colour backgroundColour,
                             PropertySet* settingsToUse)
         : DocumentWindow (title, backgroundColour, DocumentWindow::minimiseButton | DocumentWindow::closeButton),
           settings (settingsToUse),
diff --git a/modules/juce_graphics/fonts/juce_TextLayout.cpp b/modules/juce_graphics/fonts/juce_TextLayout.cpp
index de1232c5ca..ba369426fc 100644
--- a/modules/juce_graphics/fonts/juce_TextLayout.cpp
+++ b/modules/juce_graphics/fonts/juce_TextLayout.cpp
@@ -260,7 +260,7 @@ namespace TextLayoutHelpers
 
     struct Token
     {
-        Token (const String& t, const Font& f, const Colour& c, const bool whitespace)
+        Token (const String& t, const Font& f, Colour c, const bool whitespace)
             : text (t), font (f), colour (c),
               area (font.getStringWidthFloat (t), f.getHeight()),
               isWhitespace (whitespace),
@@ -415,7 +415,7 @@ namespace TextLayoutHelpers
         }
 
         void appendText (const AttributedString& text, const Range<int> stringRange,
-                         const Font& font, const Colour& colour)
+                         const Font& font, Colour colour)
         {
             const String stringText (text.getText().substring (stringRange.getStart(), stringRange.getEnd()));
             String::CharPointerType t (stringText.getCharPointer());
diff --git a/modules/juce_graphics/native/juce_win32_Direct2DGraphicsContext.cpp b/modules/juce_graphics/native/juce_win32_Direct2DGraphicsContext.cpp
index 4e44b9f45a..519557e7e8 100644
--- a/modules/juce_graphics/native/juce_win32_Direct2DGraphicsContext.cpp
+++ b/modules/juce_graphics/native/juce_win32_Direct2DGraphicsContext.cpp
@@ -722,7 +722,7 @@ private:
         return D2D1::RectF ((float) r.getX(), (float) r.getY(), (float) r.getRight(), (float) r.getBottom());
     }
 
-    static D2D1_COLOR_F colourToD2D (const Colour& c)
+    static D2D1_COLOR_F colourToD2D (Colour c)
     {
         return D2D1::ColorF::ColorF (c.getFloatRed(), c.getFloatGreen(), c.getFloatBlue(), c.getFloatAlpha());
     }
diff --git a/modules/juce_gui_basics/buttons/juce_ShapeButton.cpp b/modules/juce_gui_basics/buttons/juce_ShapeButton.cpp
index 65b11af12b..5494ca2819 100644
--- a/modules/juce_gui_basics/buttons/juce_ShapeButton.cpp
+++ b/modules/juce_gui_basics/buttons/juce_ShapeButton.cpp
@@ -22,14 +22,11 @@
   ==============================================================================
 */
 
-ShapeButton::ShapeButton (const String& text_,
-                          const Colour& normalColour_,
-                          const Colour& overColour_,
-                          const Colour& downColour_)
-  : Button (text_),
-    normalColour (normalColour_),
-    overColour (overColour_),
-    downColour (downColour_),
+ShapeButton::ShapeButton (const String& t, Colour n, Colour o, Colour d)
+  : Button (t),
+    normalColour (n),
+    overColour (o),
+    downColour (d),
     maintainShapeProportions (false),
     outlineWidth (0.0f)
 {
@@ -39,16 +36,16 @@ ShapeButton::~ShapeButton()
 {
 }
 
-void ShapeButton::setColours (const Colour& newNormalColour,
-                              const Colour& newOverColour,
-                              const Colour& newDownColour)
+void ShapeButton::setColours (Colour newNormalColour,
+                              Colour newOverColour,
+                              Colour newDownColour)
 {
     normalColour = newNormalColour;
     overColour = newOverColour;
     downColour = newDownColour;
 }
 
-void ShapeButton::setOutline (const Colour& newOutlineColour,
+void ShapeButton::setOutline (Colour newOutlineColour,
                               const float newOutlineWidth)
 {
     outlineColour = newOutlineColour;
diff --git a/modules/juce_gui_basics/buttons/juce_ShapeButton.h b/modules/juce_gui_basics/buttons/juce_ShapeButton.h
index 991ca85b3e..f87121242a 100644
--- a/modules/juce_gui_basics/buttons/juce_ShapeButton.h
+++ b/modules/juce_gui_basics/buttons/juce_ShapeButton.h
@@ -46,9 +46,9 @@ public:
         @param downColour       the colour to use when the button is in the pressed-down state
     */
     ShapeButton (const String& name,
-                 const Colour& normalColour,
-                 const Colour& overColour,
-                 const Colour& downColour);
+                 Colour normalColour,
+                 Colour overColour,
+                 Colour downColour);
 
     /** Destructor. */
     ~ShapeButton();
@@ -73,16 +73,16 @@ public:
         @param overColour       the colour to use when the mouse is over the shape
         @param downColour       the colour to use when the button is in the pressed-down state
     */
-    void setColours (const Colour& normalColour,
-                     const Colour& overColour,
-                     const Colour& downColour);
+    void setColours (Colour normalColour,
+                     Colour overColour,
+                     Colour downColour);
 
     /** Sets up an outline to draw around the shape.
 
         @param outlineColour        the colour to use
         @param outlineStrokeWidth   the thickness of line to draw
     */
-    void setOutline (const Colour& outlineColour,
+    void setOutline (Colour outlineColour,
                      float outlineStrokeWidth);
 
 
diff --git a/modules/juce_gui_basics/drawables/juce_DrawableImage.cpp b/modules/juce_gui_basics/drawables/juce_DrawableImage.cpp
index 17d0fc456b..7c29dee045 100644
--- a/modules/juce_gui_basics/drawables/juce_DrawableImage.cpp
+++ b/modules/juce_gui_basics/drawables/juce_DrawableImage.cpp
@@ -62,7 +62,7 @@ void DrawableImage::setOpacity (const float newOpacity)
     opacity = newOpacity;
 }
 
-void DrawableImage::setOverlayColour (const Colour& newOverlayColour)
+void DrawableImage::setOverlayColour (Colour newOverlayColour)
 {
     overlayColour = newOverlayColour;
 }
@@ -205,7 +205,7 @@ Colour DrawableImage::ValueTreeWrapper::getOverlayColour() const
     return Colour::fromString (state [overlay].toString());
 }
 
-void DrawableImage::ValueTreeWrapper::setOverlayColour (const Colour& newColour, UndoManager* undoManager)
+void DrawableImage::ValueTreeWrapper::setOverlayColour (Colour newColour, UndoManager* undoManager)
 {
     if (newColour.isTransparent())
         state.removeProperty (overlay, undoManager);
diff --git a/modules/juce_gui_basics/drawables/juce_DrawableImage.h b/modules/juce_gui_basics/drawables/juce_DrawableImage.h
index 103e15fa4e..47d5d190c4 100644
--- a/modules/juce_gui_basics/drawables/juce_DrawableImage.h
+++ b/modules/juce_gui_basics/drawables/juce_DrawableImage.h
@@ -67,10 +67,10 @@ public:
         This is handy for doing things like darkening or lightening an image by overlaying
         it with semi-transparent black or white.
     */
-    void setOverlayColour (const Colour& newOverlayColour);
+    void setOverlayColour (Colour newOverlayColour);
 
     /** Returns the overlay colour. */
-    const Colour& getOverlayColour() const noexcept             { return overlayColour; }
+    Colour getOverlayColour() const noexcept                    { return overlayColour; }
 
     /** Sets the bounding box within which the image should be displayed. */
     void setBoundingBox (const RelativeParallelogram& newBounds);
@@ -91,9 +91,9 @@ public:
     /** @internal */
     Rectangle<float> getDrawableBounds() const override;
     /** @internal */
-    void refreshFromValueTree (const ValueTree& tree, ComponentBuilder& builder);
+    void refreshFromValueTree (const ValueTree& tree, ComponentBuilder&);
     /** @internal */
-    ValueTree createValueTree (ComponentBuilder::ImageProvider* imageProvider) const override;
+    ValueTree createValueTree (ComponentBuilder::ImageProvider*) const override;
     /** @internal */
     static const Identifier valueTreeType;
 
@@ -105,19 +105,19 @@ public:
         ValueTreeWrapper (const ValueTree& state);
 
         var getImageIdentifier() const;
-        void setImageIdentifier (const var& newIdentifier, UndoManager* undoManager);
-        Value getImageIdentifierValue (UndoManager* undoManager);
+        void setImageIdentifier (const var&, UndoManager*);
+        Value getImageIdentifierValue (UndoManager*);
 
         float getOpacity() const;
-        void setOpacity (float newOpacity, UndoManager* undoManager);
-        Value getOpacityValue (UndoManager* undoManager);
+        void setOpacity (float newOpacity, UndoManager*);
+        Value getOpacityValue (UndoManager*);
 
         Colour getOverlayColour() const;
-        void setOverlayColour (const Colour& newColour, UndoManager* undoManager);
-        Value getOverlayColourValue (UndoManager* undoManager);
+        void setOverlayColour (Colour newColour, UndoManager*);
+        Value getOverlayColourValue (UndoManager*);
 
         RelativeParallelogram getBoundingBox() const;
-        void setBoundingBox (const RelativeParallelogram& newBounds, UndoManager* undoManager);
+        void setBoundingBox (const RelativeParallelogram&, UndoManager*);
 
         static const Identifier opacity, overlay, image, topLeft, topRight, bottomLeft;
     };
diff --git a/modules/juce_gui_basics/filebrowser/juce_FileChooserDialogBox.cpp b/modules/juce_gui_basics/filebrowser/juce_FileChooserDialogBox.cpp
index 0d8cc58b47..fed399e363 100644
--- a/modules/juce_gui_basics/filebrowser/juce_FileChooserDialogBox.cpp
+++ b/modules/juce_gui_basics/filebrowser/juce_FileChooserDialogBox.cpp
@@ -91,7 +91,7 @@ FileChooserDialogBox::FileChooserDialogBox (const String& name,
                                             const String& instructions,
                                             FileBrowserComponent& chooserComponent,
                                             const bool warnAboutOverwritingExistingFiles_,
-                                            const Colour& backgroundColour)
+                                            Colour backgroundColour)
     : ResizableWindow (name, backgroundColour, true),
       warnAboutOverwritingExistingFiles (warnAboutOverwritingExistingFiles_)
 {
diff --git a/modules/juce_gui_basics/filebrowser/juce_FileChooserDialogBox.h b/modules/juce_gui_basics/filebrowser/juce_FileChooserDialogBox.h
index 2969ff22ff..0effab4594 100644
--- a/modules/juce_gui_basics/filebrowser/juce_FileChooserDialogBox.h
+++ b/modules/juce_gui_basics/filebrowser/juce_FileChooserDialogBox.h
@@ -91,7 +91,7 @@ public:
                           const String& instructions,
                           FileBrowserComponent& browserComponent,
                           bool warnAboutOverwritingExistingFiles,
-                          const Colour& backgroundColour);
+                          Colour backgroundColour);
 
     /** Destructor. */
     ~FileChooserDialogBox();
diff --git a/modules/juce_gui_basics/layout/juce_MultiDocumentPanel.cpp b/modules/juce_gui_basics/layout/juce_MultiDocumentPanel.cpp
index 434c82d43a..78f6550403 100644
--- a/modules/juce_gui_basics/layout/juce_MultiDocumentPanel.cpp
+++ b/modules/juce_gui_basics/layout/juce_MultiDocumentPanel.cpp
@@ -22,7 +22,7 @@
   ==============================================================================
 */
 
-MultiDocumentPanelWindow::MultiDocumentPanelWindow (const Colour& backgroundColour)
+MultiDocumentPanelWindow::MultiDocumentPanelWindow (Colour backgroundColour)
     : DocumentWindow (String::empty, backgroundColour,
                       DocumentWindow::maximiseButton | DocumentWindow::closeButton, false)
 {
@@ -156,7 +156,7 @@ void MultiDocumentPanel::addWindow (Component* component)
 }
 
 bool MultiDocumentPanel::addDocument (Component* const component,
-                                      const Colour& docColour,
+                                      Colour docColour,
                                       const bool deleteWhenRemoved)
 {
     // If you try passing a full DocumentWindow or ResizableWindow in here, you'll end up
@@ -415,7 +415,7 @@ void MultiDocumentPanel::setLayoutMode (const LayoutMode newLayoutMode)
     }
 }
 
-void MultiDocumentPanel::setBackgroundColour (const Colour& newBackgroundColour)
+void MultiDocumentPanel::setBackgroundColour (Colour newBackgroundColour)
 {
     if (backgroundColour != newBackgroundColour)
     {
diff --git a/modules/juce_gui_basics/layout/juce_MultiDocumentPanel.h b/modules/juce_gui_basics/layout/juce_MultiDocumentPanel.h
index 00ded3ccc7..4de61f5a6a 100644
--- a/modules/juce_gui_basics/layout/juce_MultiDocumentPanel.h
+++ b/modules/juce_gui_basics/layout/juce_MultiDocumentPanel.h
@@ -46,20 +46,20 @@ public:
     //==============================================================================
     /**
     */
-    MultiDocumentPanelWindow (const Colour& backgroundColour);
+    MultiDocumentPanelWindow (Colour backgroundColour);
 
     /** Destructor. */
     ~MultiDocumentPanelWindow();
 
     //==============================================================================
     /** @internal */
-    void maximiseButtonPressed();
+    void maximiseButtonPressed() override;
     /** @internal */
-    void closeButtonPressed();
+    void closeButtonPressed() override;
     /** @internal */
-    void activeWindowStatusChanged();
+    void activeWindowStatusChanged() override;
     /** @internal */
-    void broughtToFront();
+    void broughtToFront() override;
 
 private:
     //==============================================================================
@@ -136,7 +136,7 @@ public:
                                     the caller must handle the component's deletion
     */
     bool addDocument (Component* component,
-                      const Colour& backgroundColour,
+                      Colour backgroundColour,
                       bool deleteWhenRemoved);
 
     /** Closes one of the documents.
@@ -233,13 +233,13 @@ public:
         Each document has its own background colour, but this is the one used to fill the areas
         behind them.
     */
-    void setBackgroundColour (const Colour& newBackgroundColour);
+    void setBackgroundColour (Colour newBackgroundColour);
 
     /** Returns the current background colour.
 
         @see setBackgroundColour
     */
-    const Colour& getBackgroundColour() const noexcept                  { return backgroundColour; }
+    Colour getBackgroundColour() const noexcept                         { return backgroundColour; }
 
     /** If the panel is being used in tabbed mode, this returns the TabbedComponent that's involved. */
     TabbedComponent* getCurrentTabbedComponent() const noexcept         { return tabComponent; }
diff --git a/modules/juce_gui_basics/layout/juce_TabbedButtonBar.cpp b/modules/juce_gui_basics/layout/juce_TabbedButtonBar.cpp
index 9f76dbb3df..cdd49bf494 100644
--- a/modules/juce_gui_basics/layout/juce_TabbedButtonBar.cpp
+++ b/modules/juce_gui_basics/layout/juce_TabbedButtonBar.cpp
@@ -227,7 +227,7 @@ void TabbedButtonBar::clearTabs()
 }
 
 void TabbedButtonBar::addTab (const String& tabName,
-                              const Colour& tabBackgroundColour,
+                              Colour tabBackgroundColour,
                               int insertIndex)
 {
     jassert (tabName.isNotEmpty()); // you have to give them all a name..
@@ -482,7 +482,7 @@ Colour TabbedButtonBar::getTabBackgroundColour (const int tabIndex)
     return tab == nullptr ? Colours::white : tab->colour;
 }
 
-void TabbedButtonBar::setTabBackgroundColour (const int tabIndex, const Colour& newColour)
+void TabbedButtonBar::setTabBackgroundColour (const int tabIndex, Colour newColour)
 {
     if (TabInfo* const tab = tabs [tabIndex])
     {
diff --git a/modules/juce_gui_basics/layout/juce_TabbedButtonBar.h b/modules/juce_gui_basics/layout/juce_TabbedButtonBar.h
index 5cfb4d4057..cc35344461 100644
--- a/modules/juce_gui_basics/layout/juce_TabbedButtonBar.h
+++ b/modules/juce_gui_basics/layout/juce_TabbedButtonBar.h
@@ -206,7 +206,7 @@ public:
         If this is the first tab added, it'll also be automatically selected.
     */
     void addTab (const String& tabName,
-                 const Colour& tabBackgroundColour,
+                 Colour tabBackgroundColour,
                  int insertIndex);
 
     /** Changes the name of one of the tabs. */
@@ -273,7 +273,7 @@ public:
     /** Changes the background colour of a tab.
         @see addTab, getTabBackgroundColour
     */
-    void setTabBackgroundColour (int tabIndex, const Colour& newColour);
+    void setTabBackgroundColour (int tabIndex, Colour newColour);
 
     //==============================================================================
     /** A set of colour IDs to use to change the colour of various aspects of the component.
diff --git a/modules/juce_gui_basics/layout/juce_TabbedComponent.cpp b/modules/juce_gui_basics/layout/juce_TabbedComponent.cpp
index 4e1a065a24..d8570afc7b 100644
--- a/modules/juce_gui_basics/layout/juce_TabbedComponent.cpp
+++ b/modules/juce_gui_basics/layout/juce_TabbedComponent.cpp
@@ -145,7 +145,7 @@ void TabbedComponent::clearTabs()
 }
 
 void TabbedComponent::addTab (const String& tabName,
-                              const Colour& tabBackgroundColour,
+                              Colour tabBackgroundColour,
                               Component* const contentComponent,
                               const bool deleteComponentWhenNotNeeded,
                               const int insertIndex)
@@ -194,7 +194,7 @@ Colour TabbedComponent::getTabBackgroundColour (const int tabIndex) const noexce
     return tabs->getTabBackgroundColour (tabIndex);
 }
 
-void TabbedComponent::setTabBackgroundColour (const int tabIndex, const Colour& newColour)
+void TabbedComponent::setTabBackgroundColour (const int tabIndex, Colour newColour)
 {
     tabs->setTabBackgroundColour (tabIndex, newColour);
 
diff --git a/modules/juce_gui_basics/layout/juce_TabbedComponent.h b/modules/juce_gui_basics/layout/juce_TabbedComponent.h
index 0c983d8bc4..2278352609 100644
--- a/modules/juce_gui_basics/layout/juce_TabbedComponent.h
+++ b/modules/juce_gui_basics/layout/juce_TabbedComponent.h
@@ -107,7 +107,7 @@ public:
         @see TabbedButtonBar::addTab
     */
     void addTab (const String& tabName,
-                 const Colour& tabBackgroundColour,
+                 Colour tabBackgroundColour,
                  Component* contentComponent,
                  bool deleteComponentWhenNotNeeded,
                  int insertIndex = -1);
@@ -134,7 +134,7 @@ public:
     Colour getTabBackgroundColour (int tabIndex) const noexcept;
 
     /** Changes the background colour of one of the tabs. */
-    void setTabBackgroundColour (int tabIndex, const Colour& newColour);
+    void setTabBackgroundColour (int tabIndex, Colour newColour);
 
     //==============================================================================
     /** Changes the currently-selected tab.
diff --git a/modules/juce_gui_basics/widgets/juce_TextEditor.cpp b/modules/juce_gui_basics/widgets/juce_TextEditor.cpp
index eb5a5f1dc3..e2fa861af9 100644
--- a/modules/juce_gui_basics/widgets/juce_TextEditor.cpp
+++ b/modules/juce_gui_basics/widgets/juce_TextEditor.cpp
@@ -1163,7 +1163,7 @@ void TextEditor::setInputRestrictions (const int maxLen,
     setInputFilter (new LengthAndCharacterRestriction (maxLen, chars), true);
 }
 
-void TextEditor::setTextToShowWhenEmpty (const String& text, const Colour& colourToUse)
+void TextEditor::setTextToShowWhenEmpty (const String& text, Colour colourToUse)
 {
     textToShowWhenEmpty = text;
     colourForTextWhenEmpty = colourToUse;
diff --git a/modules/juce_gui_basics/widgets/juce_TextEditor.h b/modules/juce_gui_basics/widgets/juce_TextEditor.h
index 2231088efd..fe2c6bd746 100644
--- a/modules/juce_gui_basics/widgets/juce_TextEditor.h
+++ b/modules/juce_gui_basics/widgets/juce_TextEditor.h
@@ -267,7 +267,7 @@ public:
         string is only displayed, it's not taken to actually be the contents of
         the editor.
     */
-    void setTextToShowWhenEmpty (const String& text, const Colour& colourToUse);
+    void setTextToShowWhenEmpty (const String& text, Colour colourToUse);
 
     //==============================================================================
     /** Changes the size of the scrollbars that are used.
diff --git a/modules/juce_gui_basics/windows/juce_DialogWindow.cpp b/modules/juce_gui_basics/windows/juce_DialogWindow.cpp
index 7a7a2b3824..186ebfd173 100644
--- a/modules/juce_gui_basics/windows/juce_DialogWindow.cpp
+++ b/modules/juce_gui_basics/windows/juce_DialogWindow.cpp
@@ -22,7 +22,7 @@
   ==============================================================================
 */
 
-DialogWindow::DialogWindow (const String& name, const Colour& colour,
+DialogWindow::DialogWindow (const String& name, Colour colour,
                             const bool escapeCloses, const bool onDesktop)
     : DocumentWindow (name, colour, DocumentWindow::closeButton, onDesktop),
       escapeKeyTriggersCloseButton (escapeCloses)
@@ -124,7 +124,7 @@ int DialogWindow::LaunchOptions::runModal()
 void DialogWindow::showDialog (const String& dialogTitle,
                                Component* const contentComponent,
                                Component* const componentToCentreAround,
-                               const Colour& backgroundColour,
+                               Colour backgroundColour,
                                const bool escapeKeyTriggersCloseButton,
                                const bool resizable,
                                const bool useBottomRightCornerResizer)
@@ -146,7 +146,7 @@ void DialogWindow::showDialog (const String& dialogTitle,
 int DialogWindow::showModalDialog (const String& dialogTitle,
                                    Component* const contentComponent,
                                    Component* const componentToCentreAround,
-                                   const Colour& backgroundColour,
+                                   Colour backgroundColour,
                                    const bool escapeKeyTriggersCloseButton,
                                    const bool resizable,
                                    const bool useBottomRightCornerResizer)
diff --git a/modules/juce_gui_basics/windows/juce_DialogWindow.h b/modules/juce_gui_basics/windows/juce_DialogWindow.h
index f5062a8da9..4ecaf5d27b 100644
--- a/modules/juce_gui_basics/windows/juce_DialogWindow.h
+++ b/modules/juce_gui_basics/windows/juce_DialogWindow.h
@@ -64,7 +64,7 @@ public:
                                     desktop; if false, you can use it as a child component
     */
     DialogWindow (const String& name,
-                  const Colour& backgroundColour,
+                  Colour backgroundColour,
                   bool escapeKeyTriggersCloseButton,
                   bool addToDesktop = true);
 
@@ -192,7 +192,7 @@ public:
     static void showDialog (const String& dialogTitle,
                             Component* contentComponent,
                             Component* componentToCentreAround,
-                            const Colour& backgroundColour,
+                            Colour backgroundColour,
                             bool escapeKeyTriggersCloseButton,
                             bool shouldBeResizable = false,
                             bool useBottomRightCornerResizer = false);
@@ -240,7 +240,7 @@ public:
     static int showModalDialog (const String& dialogTitle,
                                 Component* contentComponent,
                                 Component* componentToCentreAround,
-                                const Colour& backgroundColour,
+                                Colour backgroundColour,
                                 bool escapeKeyTriggersCloseButton,
                                 bool shouldBeResizable = false,
                                 bool useBottomRightCornerResizer = false);
diff --git a/modules/juce_gui_basics/windows/juce_DocumentWindow.cpp b/modules/juce_gui_basics/windows/juce_DocumentWindow.cpp
index 42a7bf7e5f..e63b8db687 100644
--- a/modules/juce_gui_basics/windows/juce_DocumentWindow.cpp
+++ b/modules/juce_gui_basics/windows/juce_DocumentWindow.cpp
@@ -42,9 +42,9 @@ private:
 
 //==============================================================================
 DocumentWindow::DocumentWindow (const String& title,
-                                const Colour& backgroundColour,
-                                const int requiredButtons_,
-                                const bool addToDesktop_)
+                                Colour backgroundColour,
+                                int requiredButtons_,
+                                bool addToDesktop_)
     : ResizableWindow (title, backgroundColour, addToDesktop_),
       titleBarHeight (26),
       menuBarHeight (24),
diff --git a/modules/juce_gui_basics/windows/juce_DocumentWindow.h b/modules/juce_gui_basics/windows/juce_DocumentWindow.h
index cb4fdfdaed..6bc0108f19 100644
--- a/modules/juce_gui_basics/windows/juce_DocumentWindow.h
+++ b/modules/juce_gui_basics/windows/juce_DocumentWindow.h
@@ -89,7 +89,7 @@ public:
         @see TitleBarButtons
     */
     DocumentWindow (const String& name,
-                    const Colour& backgroundColour,
+                    Colour backgroundColour,
                     int requiredButtons,
                     bool addToDesktop = true);
 
diff --git a/modules/juce_gui_basics/windows/juce_ResizableWindow.cpp b/modules/juce_gui_basics/windows/juce_ResizableWindow.cpp
index 45c5ca057e..f3ad59680c 100644
--- a/modules/juce_gui_basics/windows/juce_ResizableWindow.cpp
+++ b/modules/juce_gui_basics/windows/juce_ResizableWindow.cpp
@@ -37,7 +37,7 @@ ResizableWindow::ResizableWindow (const String& name,
 }
 
 ResizableWindow::ResizableWindow (const String& name,
-                                  const Colour& backgroundColour_,
+                                  Colour backgroundColour_,
                                   const bool addToDesktop_)
     : TopLevelWindow (name, addToDesktop_),
       ownsContentComponent (false),
@@ -401,7 +401,7 @@ Colour ResizableWindow::getBackgroundColour() const noexcept
     return findColour (backgroundColourId, false);
 }
 
-void ResizableWindow::setBackgroundColour (const Colour& newColour)
+void ResizableWindow::setBackgroundColour (Colour newColour)
 {
     Colour backgroundColour (newColour);
 
diff --git a/modules/juce_gui_basics/windows/juce_ResizableWindow.h b/modules/juce_gui_basics/windows/juce_ResizableWindow.h
index b0cc95b702..1b2dd4fc04 100644
--- a/modules/juce_gui_basics/windows/juce_ResizableWindow.h
+++ b/modules/juce_gui_basics/windows/juce_ResizableWindow.h
@@ -75,7 +75,7 @@ public:
                                     desktop; if false, you can use it as a child component
     */
     ResizableWindow (const String& name,
-                     const Colour& backgroundColour,
+                     Colour backgroundColour,
                      bool addToDesktop);
 
     /** Destructor.
@@ -110,7 +110,7 @@ public:
 
         @see getBackgroundColour
     */
-    void setBackgroundColour (const Colour& newColour);
+    void setBackgroundColour (Colour newColour);
 
     //==============================================================================
     /** Make the window resizable or fixed.
diff --git a/modules/juce_gui_basics/windows/juce_TopLevelWindow.h b/modules/juce_gui_basics/windows/juce_TopLevelWindow.h
index 6383109e0f..39610f13ba 100644
--- a/modules/juce_gui_basics/windows/juce_TopLevelWindow.h
+++ b/modules/juce_gui_basics/windows/juce_TopLevelWindow.h
@@ -128,7 +128,7 @@ public:
 
     //==============================================================================
     /** @internal */
-    virtual void addToDesktop (int windowStyleFlags, void* nativeWindowToAttachTo = nullptr);
+    virtual void addToDesktop (int windowStyleFlags, void* nativeWindowToAttachTo = nullptr) override;
 
 protected:
     //==============================================================================
diff --git a/modules/juce_gui_extra/misc/juce_PreferencesPanel.cpp b/modules/juce_gui_extra/misc/juce_PreferencesPanel.cpp
index 40c6b0c26b..9d4c579a71 100644
--- a/modules/juce_gui_extra/misc/juce_PreferencesPanel.cpp
+++ b/modules/juce_gui_extra/misc/juce_PreferencesPanel.cpp
@@ -79,7 +79,7 @@ void PreferencesPanel::addSettingsPage (const String& title, const void* imageDa
 }
 
 //==============================================================================
-void PreferencesPanel::showInDialogBox (const String& dialogTitle, int dialogWidth, int dialogHeight, const Colour& backgroundColour)
+void PreferencesPanel::showInDialogBox (const String& dialogTitle, int dialogWidth, int dialogHeight, Colour backgroundColour)
 {
     setSize (dialogWidth, dialogHeight);
 
diff --git a/modules/juce_gui_extra/misc/juce_PreferencesPanel.h b/modules/juce_gui_extra/misc/juce_PreferencesPanel.h
index 4e19cb88d7..6852bb39aa 100644
--- a/modules/juce_gui_extra/misc/juce_PreferencesPanel.h
+++ b/modules/juce_gui_extra/misc/juce_PreferencesPanel.h
@@ -102,7 +102,7 @@ public:
     void showInDialogBox (const String& dialogTitle,
                           int dialogWidth,
                           int dialogHeight,
-                          const Colour& backgroundColour = Colours::white);
+                          Colour backgroundColour = Colours::white);
 
     //==============================================================================
     /** Subclasses must override this to return a component for each preferences page.