I can only say that I love Blu-Kote, or wound dust, or whatever you call it. Sulpha powder and charcoal dust in puffer bottle is hard to beat for basic wound care. If it was good
enough for our soldiers, it's good enough for my
chickens.
It's blue,
chickens leave it alone, and it works well.
I also have ordinary sulpha in a yellow powder that I picked up somewhere. It's a yellow dust, in a puffer bottle. It doesn't stay yellow, but it tastes bad enough the dog I used it on wouldn't lick the wound which was a plus.
The problem with coloring ointments is the reaction of the color with air and wounds. Tincture of iodine stains, but it's not the color you're looking for. If you really wanted to experiment with some salves and food coloring, I'd suggest using the powdered pigments used for "natural dying" of fabrics as anything else would probably be too light in color to make a difference. Try making up a hand cream salve using the basic stuff you'd want to use as a wound treatment, and add different amount of the pigments. Some of them are used in herbalism (not many and nothing jumps to mind), but I'm sure you could find something. Then try it on your hands/arms and see if it gives the kind of coverage and effect you want. Experiment. Maybe you'll find something you can market and
sell to the rest of us.
About the carcinogen thing? Oxygen is carcinogenic. Everything is eventually carcinogenic. LIFE is carcinogenic - the longer you live, the more errors end up in your cellular structure and the shorter the replicating DNA strands for your cells. Eventually you'd become an odd looking lump, just from living long enough to get there. Don't be afraid of living. Make your choices based on what's important to you and move on.