When the device is in Dark Mode and you have a switch inside a layout with BackgroundColor = "White" switch's Off track color it's also set to White, and you only can see the Thumb.

Simply put, no.
Why would something like this not be editable? The track colour should be editable in both the on and off states, not just in the on state.

I think TrackColor works with both on and off. Then toggle the color depending on the on/off state and you should be able to implement this functionality.

In general, after working with XAML for a while, you get into a mode so that you expect certain behaviors as Properties. I'm just saying that you would rather try to set something via "TrackOnColor" and "TrackOffColor" than setting big state groups:

<Switch IsToggled="True">
    <VisualStateManager.VisualStateGroups>
        <VisualStateGroup x:Name="CommonStates">
            <VisualState x:Name="On">
                <VisualState.Setters>
                    <Setter Property="ThumbColor"
                            Value="MediumSpringGreen" />
                </VisualState.Setters>
            </VisualState>
            <VisualState x:Name="Off">
                <VisualState.Setters>
                    <Setter Property="ThumbColor"
                            Value="Red" />
                </VisualState.Setters>
            </VisualState>
        </VisualStateGroup>
    </VisualStateManager.VisualStateGroups>
</Switch>

This is just a general thing and preference for me. It is also more intuitive to browse the IntelliSense within a Control in XAML for certain properties.

So if you come to the point where you discuss internally how something new is going to be implemented 😊

Hi @jfversluis and @MAUIoxo ,
the ThumbColor works. But the switch has only a OnColor property which colours the track. Using this VisualState:

  <Switch IsToggled="True"
          Margin="10,0,15,0"
          VerticalOptions="Center">
    <VisualStateManager.VisualStateGroups>
      <VisualStateGroup x:Name="CommonStates">
        <VisualState x:Name="On">
          <VisualState.Setters>
            <Setter Property="ThumbColor"
                    Value="MediumSpringGreen" />
            <Setter Property="OnColor"
                    Value="MediumSpringGreen" />
          </VisualState.Setters>
        </VisualState>
        <VisualState x:Name="Off">
          <VisualState.Setters>
            <Setter Property="ThumbColor"
                    Value="Red" />
            <Setter Property="OnColor"
                    Value="Red" />
          </VisualState.Setters>
        </VisualState>
      </VisualStateGroup>
    </VisualStateManager.VisualStateGroups>
  </Switch>

results in a grey track if off:

My preference is still, to have "OnThumbColor", "OffThumbColor", "OnTrackColor" and "OffTrackColor" - most obvious to me and regarding a clean API clearest

I have run into this issue on Android. When the background color is black, the track color is also black, so you can only see the thumb. On Windows, this is not a problem because the switch control has an outline around it.

Update: I found that setting the DefaultNightMode to ModeNightYes in the Android application code makes the track tint lighter so that you can see it on a dark background. I was previously just setting the UserAppTheme. It seems that if you can update the Android DefaultNightMode to match the UserAppTheme, this will solve the track visibility issue.

Thanks for the sample. It's less than ideal to have to write our own just to address built-in behavior producing an invisible track, but it wouldn't be the first time.

@TheXenocide I rewrote my answer deleting the massive customization. The answer now shows a minimalistic way to achieve an off color.

Using the BackgroundColor is a very smart idea since we normally don't use that for a switch! It looks great on Windows. Unfortunately, this might not work for Android because the Thumb is larger than the track, so Clip will also cut off part of the thumb. (We'd also need different sizes and shapes of the track for each platform.)

Just to give some extra info, there is actually no such thing as a "track color" in dark mode, but actually a little shading effect applied to the background, which ends up being hard to see on dark mode (try to shade some already dark color...)
Screenshot to illustrate, I added a red background to the first switch :

We either need a TrackColor property which would replace OnColor and can be handled by the on and off Visual States, or add an OffColor property in addition to the OnColor property.

@chrond I rewrote my answer to demonstrate how you can get OffColor. #21863 (comment)

@stephenquan That's a slick hack. Thanks for the idea!

It's actually coming in .NET 10!
https://github.com/dotnet/core/blob/main/release-notes/10.0/preview/preview2/dotnetmaui.md#switchoffcolor