Not a feedback for the forum but on this specific OP, I noticed that on dark theme, the blue and green highlight with hardcoded color show low contrast making it hard/impossible to read text unless I highlight it, see screenshot below:
Although, that could be turned into a forum suggestion: support smart/dynamic text highlight (automatically chose lightness opposite to theme so that it always contrasts with text - would need a custom syntax to be able to support a certain set of colors for both dark and light themes, though)
Or a more general settings suggestion: add a little button to toggle dark/light theme at top-right of page to quickly change it if needed, without having to go to Settings (but so far I only found this particular OP where I needed to do that)