diff --git a/src/plugins/platforms/cocoa/qcocoabackingstore.h b/src/plugins/platforms/cocoa/qcocoabackingstore.h
index a874936ce6..b57deacb57 100644
--- a/src/plugins/platforms/cocoa/qcocoabackingstore.h
+++ b/src/plugins/platforms/cocoa/qcocoabackingstore.h
@@ -54,8 +54,6 @@ class QCocoaBackingStore : public QRasterBackingStore
 protected:
     QCocoaBackingStore(QWindow *window);
     QCFType<CGColorSpaceRef> colorSpace() const;
-    QMacNotificationObserver m_backingPropertiesObserver;
-    virtual void backingPropertiesChanged() = 0;
 };
 
 class QNSWindowBackingStore : public QCocoaBackingStore
@@ -71,7 +69,6 @@ private:
     bool windowHasUnifiedToolbar() const;
     QImage::Format format() const override;
     void redrawRoundedBottomCorners(CGRect) const;
-    void backingPropertiesChanged() override;
 };
 
 class QCALayerBackingStore : public QCocoaBackingStore
@@ -118,7 +115,8 @@ private:
     bool recreateBackBufferIfNeeded();
     bool prepareForFlush();
 
-    void backingPropertiesChanged() override;
+    void backingPropertiesChanged();
+    QMacNotificationObserver m_backingPropertiesObserver;
 
     std::list<std::unique_ptr<GraphicsBuffer>> m_buffers;
 };
diff --git a/src/plugins/platforms/cocoa/qcocoabackingstore.mm b/src/plugins/platforms/cocoa/qcocoabackingstore.mm
index b17302a640..8a815a7665 100644
--- a/src/plugins/platforms/cocoa/qcocoabackingstore.mm
+++ b/src/plugins/platforms/cocoa/qcocoabackingstore.mm
@@ -51,17 +51,6 @@ QT_BEGIN_NAMESPACE
 QCocoaBackingStore::QCocoaBackingStore(QWindow *window)
     : QRasterBackingStore(window)
 {
-    // Ideally this would be plumbed from the platform layer to QtGui, and
-    // the QBackingStore would be recreated, but we don't have that code yet,
-    // so at least make sure we invalidate our backingstore when the backing
-    // properties (color space e.g.) are changed.
-    NSView *view = static_cast<QCocoaWindow *>(window->handle())->view();
-    m_backingPropertiesObserver = QMacNotificationObserver(view.window,
-        NSWindowDidChangeBackingPropertiesNotification, [this]() {
-            qCDebug(lcQpaBackingStore) << "Backing properties for"
-                << this->window() << "did change";
-            backingPropertiesChanged();
-        });
 }
 
 QCFType<CGColorSpaceRef> QCocoaBackingStore::colorSpace() const
@@ -341,11 +330,6 @@ void QNSWindowBackingStore::redrawRoundedBottomCorners(CGRect windowRect) const
 #endif
 }
 
-void QNSWindowBackingStore::backingPropertiesChanged()
-{
-    m_image = QImage();
-}
-
 // ----------------------------------------------------------------------------
 
 QCALayerBackingStore::QCALayerBackingStore(QWindow *window)
@@ -353,6 +337,18 @@ QCALayerBackingStore::QCALayerBackingStore(QWindow *window)
 {
     qCDebug(lcQpaBackingStore) << "Creating QCALayerBackingStore for" << window;
     m_buffers.resize(1);
+
+    // Ideally this would be plumbed from the platform layer to QtGui, and
+    // the QBackingStore would be recreated, but we don't have that code yet,
+    // so at least make sure we update our backingstore when the backing
+    // properties (color space e.g.) are changed.
+    NSView *view = static_cast<QCocoaWindow *>(window->handle())->view();
+    m_backingPropertiesObserver = QMacNotificationObserver(view.window,
+        NSWindowDidChangeBackingPropertiesNotification, [this]() {
+            qCDebug(lcQpaBackingStore) << "Backing properties for"
+                << this->window() << "did change";
+            backingPropertiesChanged();
+        });
 }
 
 QCALayerBackingStore::~QCALayerBackingStore()
@@ -620,8 +616,9 @@ QImage QCALayerBackingStore::toImage() const
 
 void QCALayerBackingStore::backingPropertiesChanged()
 {
-    m_buffers.clear();
-    m_buffers.resize(1);
+    qCDebug(lcQpaBackingStore) << "Updating color space of existing buffers";
+    for (auto &buffer : m_buffers)
+        buffer->setColorSpace(colorSpace());
 }
 
 QPlatformGraphicsBuffer *QCALayerBackingStore::graphicsBuffer() const
@@ -698,10 +695,11 @@ bool QCALayerBackingStore::prepareForFlush()
 
 QCALayerBackingStore::GraphicsBuffer::GraphicsBuffer(const QSize &size, qreal devicePixelRatio,
                                 const QPixelFormat &format, QCFType<CGColorSpaceRef> colorSpace)
-    : QIOSurfaceGraphicsBuffer(size, format, colorSpace)
+    : QIOSurfaceGraphicsBuffer(size, format)
     , dirtyRegion(0, 0, size.width() / devicePixelRatio, size.height() / devicePixelRatio)
     , m_devicePixelRatio(devicePixelRatio)
 {
+    setColorSpace(colorSpace);
 }
 
 QImage *QCALayerBackingStore::GraphicsBuffer::asImage()
diff --git a/src/plugins/platforms/cocoa/qcocoaintegration.mm b/src/plugins/platforms/cocoa/qcocoaintegration.mm
index b7f15a2bf1..d8c931e9a1 100644
--- a/src/plugins/platforms/cocoa/qcocoaintegration.mm
+++ b/src/plugins/platforms/cocoa/qcocoaintegration.mm
@@ -396,6 +396,8 @@ QVariant QCocoaIntegration::styleHint(StyleHint hint) const
         return QCoreTextFontEngine::fontSmoothingGamma();
     case ShowShortcutsInContextMenus:
         return QVariant(false);
+    // case CursorFlashTime:
+    //     return 50000;
     default: break;
     }
 
diff --git a/src/plugins/platforms/cocoa/qiosurfacegraphicsbuffer.h b/src/plugins/platforms/cocoa/qiosurfacegraphicsbuffer.h
index 872773cb7a..e070ba977d 100644
--- a/src/plugins/platforms/cocoa/qiosurfacegraphicsbuffer.h
+++ b/src/plugins/platforms/cocoa/qiosurfacegraphicsbuffer.h
@@ -48,9 +48,11 @@ QT_BEGIN_NAMESPACE
 class QIOSurfaceGraphicsBuffer : public QPlatformGraphicsBuffer
 {
 public:
-    QIOSurfaceGraphicsBuffer(const QSize &size, const QPixelFormat &format, QCFType<CGColorSpaceRef> colorSpace);
+    QIOSurfaceGraphicsBuffer(const QSize &size, const QPixelFormat &format);
     ~QIOSurfaceGraphicsBuffer();
 
+    void setColorSpace(QCFType<CGColorSpaceRef> colorSpace);
+
     const uchar *data() const override;
     uchar *data() override;
     int bytesPerLine() const override;
diff --git a/src/plugins/platforms/cocoa/qiosurfacegraphicsbuffer.mm b/src/plugins/platforms/cocoa/qiosurfacegraphicsbuffer.mm
index a367487e85..285e316d4a 100644
--- a/src/plugins/platforms/cocoa/qiosurfacegraphicsbuffer.mm
+++ b/src/plugins/platforms/cocoa/qiosurfacegraphicsbuffer.mm
@@ -53,7 +53,7 @@ QT_BEGIN_NAMESPACE
 
 Q_LOGGING_CATEGORY(lcQpaIOSurface, "qt.qpa.backingstore.iosurface");
 
-QIOSurfaceGraphicsBuffer::QIOSurfaceGraphicsBuffer(const QSize &size, const QPixelFormat &format, QCFType<CGColorSpaceRef> colorSpace)
+QIOSurfaceGraphicsBuffer::QIOSurfaceGraphicsBuffer(const QSize &size, const QPixelFormat &format)
     : QPlatformGraphicsBuffer(size, format)
 {
     const size_t width = size.width();
@@ -81,17 +81,19 @@ QIOSurfaceGraphicsBuffer::QIOSurfaceGraphicsBuffer(const QSize &size, const QPix
 
     Q_ASSERT(size_t(bytesPerLine()) == bytesPerRow);
     Q_ASSERT(size_t(byteCount()) == totalBytes);
-
-    if (colorSpace) {
-        IOSurfaceSetValue(m_surface, CFSTR("IOSurfaceColorSpace"),
-            QCFType<CFPropertyListRef>(CGColorSpaceCopyPropertyList(colorSpace)));
-    }
 }
 
 QIOSurfaceGraphicsBuffer::~QIOSurfaceGraphicsBuffer()
 {
 }
 
+void QIOSurfaceGraphicsBuffer::setColorSpace(QCFType<CGColorSpaceRef> colorSpace)
+{
+    Q_ASSERT(colorSpace);
+    IOSurfaceSetValue(m_surface, CFSTR("IOSurfaceColorSpace"),
+        QCFType<CFPropertyListRef>(CGColorSpaceCopyPropertyList(colorSpace)));
+}
+
 const uchar *QIOSurfaceGraphicsBuffer::data() const
 {
     return (const uchar *)IOSurfaceGetBaseAddress(m_surface);