Changing colors in Developer mode wont stick!

Hello everyone! I am 2 months into “crypto” and Cardano was one of my first. After looking into it I realized I had no idea what i had got myself into! Now I must go deeper, so I joined this forum to learn more. I would like to introduce myself with this question:
How can I get color changes to stick after closing Daedalus?
I’ve tried altering the files in “themes” using wordpad and also painstakingly selecting them in Developer mode, but sadly they just wont stick… I would much appreciate any information on how to make lasting changes to my wallet , besides acquiring more ADA, that is!