Thanks for the suggestions. I really like the navigation on the browser and didn't like tapatalk so rules that out. The Chrome extension doesn't work on Android (apparently no add ons because of ad blocking).
I've resorted to installing Firefox and dark reader add on, not the greatest solution for one site but gets it done.
I've used plenty of forums with multiple themes, normally adjusted in the settings by each user using a drop down menu. Mods, I know you're busy but it's a pretty simple process. You could go to the point of themes to match race teams but that's getting into the old MySpace themes realm lol.