Other possibilities, in a myriad of possibilities! Honey bees and bumble bees will often collect, in addition to pollen, brightly colored fungicidal powders that are applied to their host plants. I remember one type of fungicide being BRIGHT RED. The pollen loads the bees carried were deep vermilion. You should also be cautious of pollination biologists using brightly colored pollen analogues (dyes, most often) in their field experiments. I have also observed honey bees collecting catkin pollen when nothing else is available. In addition to being very colorful, catkin pollen is noticeably abundant early on. Honey bees may also collect inert particles that have the same consistency of pollen, these my be used for building materials, perhaps propolis. Also, some wild bees are partial to particles of freshly sanded paint. Anyway, this discussion will undoubtably add insult to injury. Good hunting all... Discombobulatingly Yours, Blair Blair J Sampson Dept. of Entomology Auburn University Auburn, Alabama 36849-5413 U.S.A. [log in to unmask]