Windows Accent Color Coming Through

[under3415]

If I change the Windows 10 accent color, I can see this color (lime) come through instead of the in-app selected accent color (blue) in some cases (e.g. mouse hover over check box). See image.

Interestingly, this happens for mouse hover in both Light and Dark themes for check boxes, radio buttons and slider controls, but only in Dark theme for toggle switch control.

[under3415]

Found that in my app this had to do with merging resources.

When I had this in app.xaml (for WinUI controls)

    <Application.Resources>
                            <XamlControlsResources xmlns="using:Microsoft.UI.Xaml.Controls" />
    </Application.Resources>

and this in Page resources

<Page.Resources>
           <ResourceDictionary>
               <ResourceDictionary.MergedDictionaries>
                   <ResourceDictionary Source="ThemeDictionary.xaml"/>
               </ResourceDictionary.MergedDictionaries>
           </ResourceDictionary>
   </Page.Resources>

I was getting all sort of color weirdness. Sometimes theme colors would be used and in other cases the Windows OS colors would be used.

When I put both in app.xaml, that fixed the issue. Not sure why you still have it in your app, maybe check merging?

  <Application.Resources>
            <ResourceDictionary>
                <ResourceDictionary.MergedDictionaries>
                    <XamlControlsResources xmlns="using:Microsoft.UI.Xaml.Controls" />
                    <ResourceDictionary Source="ThemeDictionary.xaml"/>
                </ResourceDictionary.MergedDictionaries>
            </ResourceDictionary>
    </Application.Resources>