Edit: The user script still works with the new update forums. Hell I think it looks even better now.
I created a custom theme script for the forums. With easy to edit theme colors.
I kind of themed the colors after tf2maps cause I like their style.
This script is for use in Tampermonkey, GreaseMonkey, or what-ever user script extension you use.
If you want to change the colors edit the first
addGlobalStyle line, the one with :root, and change the color hex values there.
https://jump.tf/forum/index.php?action=dlattach;topic=3072.0;attach=1131Here are some screenshots.
These are examples of custom colors.