It was a random thought that came to me during a long, boring zoom meeting and out of that boredom I used my permanent markers to try coloring one of my cheaper onaholes, which looked fantastic initially but failed to stay.

Afterwards I found that the only way to color silicone material is by mixing a dye during the process.
Ready to give up I perchance found an article about silicone paint, which by itself is colorless and needs pigments to give it color. I tried it out on the most recent Taimanin onahole and the results were amazing. I would post pictures but there's rules against that here. When completely dried the silicone has a nice smooth polish texture. She looked sexy with a shiny purple thong, blue bikini, and blue, silver mixed armor with traces of gold. Painted part of the thighs black to make it look like she's wearing smooth stocking.

The silicone paint I eventually got was called Psycho Paint A&B (they come as a set that you have to mix)
I got two different sets of pigments a liquid set (designed for silicone), and a powder metallic set.

You only need a small amount because the paint has a tendency to slowly drip down if you apply a thick layer. The best way is to apply a small layer, wait for it to harden and continue to apply thin layers to have the color get deeper. Paper towels will be your best friend especially on keeping your equipment clean (pulling dry silicone off a brush sucks so wipe it on paper towel each time).