This is gamemode what was popular in counter-strike 1.6, but didn't make till CS:GO, atleast for public release. Deffinetly some credits go to Mitchell for his https://github.com/MitchDizzle/PaintBall , because some things are taken from here, but still this version is little bit different.
Mostly you can use any map, but I suggest to use maps without many models, because decals of the paintball balls doesn't show up on models, but only on brushes.