I use a wiiiiiide variety of colors, i've used brick, wine, but I also use like a chocolate brown, I think its called bittersweet chocolate. just kind of mix them together to get a look you like. also keep a cup of water handy to thin it out, it does give it a grungy dirty old feel. I like to give my props and costumes the dirty old blood base then lighten the colors as a fresh new blood look. (like base brown then layer with the top being red apple or crimson red and even cardinal red)