I've done food coloring in 4004 and in minwax one coat. Bleeds like crazy into the next layers. Couldn't stop it. Also not as concentrated as one would think. Ended up at like 25 percent to get good color. Id like to try alumilite resin dyes. I believe they are aniline dye like candy is. I've used them in polyester resin for fiberglass molds and they are super concentrated. 5 or six drops to a quart gave good enough color to overpower the resins natural color. That was with yellow into pink resin.