I highly recommend to start doing it!
You will run into problems you currently didn’t even think of. But don’t be afraid, the problems would be solvable.
Just some general thoughts about making mods:
- what do you want to have, how should the final result look/feel/play like.
- what changes have to be made to which module (game, cgame, ui).
- search the whole codebase (game, cgame, ui) for already existing code you can reuse.
- search the Internet for tutorials (I already pointed you to some awesome tutorials)*.
- bigger projects (like 3 team ctf) will profit from version control software (put your mod on github).
- start with the game logic, than do the cgame stuff (effects, HUD, ui, whatnot).
- don’t expect others to do the work for you,
- but always feel free to ask for help if you can’t fix a problem you tried to solve for hours by your self.
- always do testing your code with some friends, sometimes others don’t like the things you deem as good.
- release, advertise, praise your code, and have fun!
*If you don’t like E-tutorials, I highly recommend this one: Focus on mod programming for Quake 3 Arena
There is a chapter explaining how to reuse existing flags for other colors, iirc…
Of course, you can make white skins, you need a paint program to do this…, this isn’t really related to programming.