itch.io

Well, yeah. The version you're currently using doesn't have a way to access this menu but I've created a quick patched version for Android that has the accessibility settings in the quick menu at the bottom once you're in the game.
Just download the "CrimsonHigh-v0.29.1.1.apk" from here and install that, then you should have access to the accessibility menu.
You might have to restart the application once after enabling the "High Contrast Text" setting for it to take effect but then it should do what you're looking for (white text on black background).

Quick disclaimer: This is a short-term fix and I haven't had the time to fully test it, so it might not fully work. That I can only guarantee for the next actual update (v0.30). So, if you do try this version, please keep this in mind. Any errors that might pop up aren't indicative of CH's usual quality and a product of this band-aid solution. I still hope it works for you and wish you a good time with the game! :)