Editing the UI is pretty complicated (such that most hacks barely touch it, if at all). I don’t think there’s an easy way to make the game invert select colours in specific circumstances that would look acceptable.
There’s probably a way to do completely inverted colours, but that’s probably not what you want. Eg.
I know Huichelaar did a hue shift hack which lags the game and makes everything look like a disco.
You could also look into gba emulator settings / filters.
Sorry to disappoint you.