this same thing happened to me with the dark purple theme!!!!! lol.
But I checked out https://minimeters.app/help/theming , there is your color customization for now (each theme is a text file that used to be .txt, now it's .ini, check the page for info). I'm trying to recall the colors that I liked from memory and failing a bit but this is pretty complete, and if you use something like VSCode or any other program that lets you pick colors in place and writes them as rgb(x,y,z) then you're even comfier (if not just try something like https://rgbcolorpicker.com/