War Paint, also known simply as WP, is one of the first two Patch markings ever created, and unlike the rest of the patch marks has an item specifically created for that purpose, a War Paint flower/plant. The same goes for the marking Rings. These two are no longer being sold in shops and can't be found in the gathering areas.
It is a large marking, taking up almost the same amount of space as Husky, but just like Rings and all the other Patch markings, it's very distinctive and hard to mistake for another marking unless heavily covered.
While it IS at the moment very hard to find the plant that will give you War Paint to add on to your feli, there are some users who have ONLY this marking on their feli and use their DNA to help genecode.