Ok, here is the "Spray Paint" weapon. Should work straight forward. Drop the entity anywhere you wish into your entitybank.
The weapon I placed under the "modernday" guns folder. Now two things to remember...
#1: The "bulletholes" I included a backup copy. If you open the bullethole.dds file you'll notice the top left one I changed for "spray paint" (change the color to suit your need)
The top left is slot-#0. IF ANY OTHER OF YOUR WEAPONS use slot #0 for a bullet hole, this "paint" decal will show, you will have to change the weapons scorchtype slot # in it's gunspec file (scorchtype = 0 thru 15 )
#2: Note, any wall you intend to paint, the segments .fps file need their "material index changed to "0" (materialindex0 = 0) most have 16 parts/index's

If you don't change it to zero, the wall will have shards & debris when painting
Any other problems, please let me know....thanks, enjoy
My games never have bugs. They just develop random features..
Lots and lots of random features...