diff --git a/plugins/3MFReader/WorkspaceDialog.qml b/plugins/3MFReader/WorkspaceDialog.qml
index d0250abfd8..d00e12e9ee 100644
--- a/plugins/3MFReader/WorkspaceDialog.qml
+++ b/plugins/3MFReader/WorkspaceDialog.qml
@@ -17,6 +17,7 @@ UM.Dialog
     minimumWidth: UM.Theme.getSize("popup_dialog").width
     minimumHeight: UM.Theme.getSize("popup_dialog").height
     width: minimumWidth
+    backgroundColor: UM.Theme.getColor("main_background")
     margin: UM.Theme.getSize("default_margin").width
     property int comboboxHeight: UM.Theme.getSize("default_margin").height
 
diff --git a/plugins/PostProcessingPlugin/PostProcessingPlugin.qml b/plugins/PostProcessingPlugin/PostProcessingPlugin.qml
index c252f13c68..46d05511cf 100644
--- a/plugins/PostProcessingPlugin/PostProcessingPlugin.qml
+++ b/plugins/PostProcessingPlugin/PostProcessingPlugin.qml
@@ -19,7 +19,7 @@ UM.Dialog
     height: 500 * screenScaleFactor
     minimumWidth: 400 * screenScaleFactor
     minimumHeight: 250 * screenScaleFactor
-
+    backgroundColor: UM.Theme.getColor("main_background")
     onVisibleChanged:
     {
         // Whenever the window is closed (either via the "Close" button or the X on the window frame), we want to update it in the stack.
diff --git a/resources/qml/Dialogs/AboutDialog.qml b/resources/qml/Dialogs/AboutDialog.qml
index 6687da572d..18d60ae1bc 100644
--- a/resources/qml/Dialogs/AboutDialog.qml
+++ b/resources/qml/Dialogs/AboutDialog.qml
@@ -19,6 +19,8 @@ UM.Dialog
     width: minimumWidth
     height: minimumHeight
 
+    backgroundColor: UM.Theme.getColor("main_background")
+
     Rectangle
     {
         id: header
diff --git a/resources/qml/Dialogs/AskOpenAsProjectOrModelsDialog.qml b/resources/qml/Dialogs/AskOpenAsProjectOrModelsDialog.qml
index 65d62a5fab..cac23d34c1 100644
--- a/resources/qml/Dialogs/AskOpenAsProjectOrModelsDialog.qml
+++ b/resources/qml/Dialogs/AskOpenAsProjectOrModelsDialog.qml
@@ -17,6 +17,7 @@ UM.Dialog
     title: catalog.i18nc("@title:window", "Open project file")
     width: UM.Theme.getSize("small_popup_dialog").width
     height: UM.Theme.getSize("small_popup_dialog").height
+    backgroundColor: UM.Theme.getColor("main_background")
 
     maximumHeight: height
     maximumWidth: width