Extra Mainframe

I'm wondering how difficult to add extra colors would be to mainframe I am pretty proficient at modifying styles. I've made some uhd conversions of mainframe templates, I have really dorky quirks and flaws to make sure they don't get confused for real magic cards, just as a note. That's besides the point. Could I take some of the files from extras and intigrate them or do I need to rewrite most of the code. Regardless I'm up for the challenge. Just would like some pointers.