For some reason, on Stratics, the paint doesn't show up in item search on the main page, I always have to find it on the page that has special items listed.
You lose the paint effect if you die, attack an NPC savage or after week of play time.
From the
FAQ:
A skilled cook can create savage kin paint from a tribal berry
and some flour. You must have an 80.0 skill in Cooking to do so. Note that the tribal berry is not edible, so you need not worry about mistakenly double-clicking on them. You can apply savage kin paint to your skin to get the same looks as a savage. A pot of paint can only be used once. The paint will stay on for one week of play time, providing you don't die. When you die, the paint stays on the corpse's skin. An oilcloth can be used to wipe the paint off. In the 2D client your skin will be grey, in the 3D client your skin will show the typical savage markings. Tribal berries can be found as loot on
savages.
Applying the paint make you lose some karma. When you are painted, savages will not attack you. If you attack a savage while painted, the paint will burn off, doing about 50 points of damage. You cannot wear a mask of orcish kin when you are painted, so you will have to take sides in the savage vs. orcs war. You can, however, wear an evil orc helm while painted.
Bug: Make sure you are not carrying any honey when you make the paint. The paint will combine with the honey and thus be detroyed.
-Skylark