It's blood. Believe it or not, the game's really gory, so it really matches th- I'm just kidding, it's definitely paint splatter.
I suppose this is technically, in a way, a gift to me as well(just feeding my own ego), and I feel bad because I wasn't participating in the secret Santa. I know it's directed at Seiromem techincally. Nevertheless, THANKS Nessiah. It's fricking brilliant. We love it :D.