I know there was a post about this a while back, but I can't seem to find it. My FMIL bought some clear water beads for my shower, and wants to dye the water red. The flowers that are going in the vase are fake, so it won't matter if the dye could be soaked into a living flower. What is the best thing to use to dye the water beads? Food coloring? Water color paint? Any ideas?