There is nothing, as far as I know, that violates the ToS. It’s appropriate and isn’t misleading. Unless you are manipulating the dark theme to somehow bypass the filter (ex. show bypassed words/images that would not show up on non dark mode) then it will be allowed.
As the @L7_M and @ZehTopHat, I can’t really see anything against the ToS, but keep that in mind, ambiguous things can be interpreted in more than one way so it could be a slightly change of it not being approved. Best of luck and in my opinion it looks good.