Watercolour addict

Amongst other oddities, one or our cats has become addicted to the taste of watercolor cubes. If I don't watch out and leave the desk for 5 minutes, she'll be licking the paint off my metallic painting kit, or drinking the dirty paint water, or even - my favorite- licking the wet paint off the drawing I'm working on. Considering that she is still alive despite the quantities of the stuff that she has ingested by now, I'm guessing it's not too toxic.