rober and Riverrat, I use Posca paint pens, scentless bright colors. I have 3 hives and 6 nucs and all those queens are painted pink, and all those queens are still with me. I posted a pic of my first pink queen this spring and Tecumse said that they liked the color pink in their lab as well.
Riverrat, it could be.. maybe.. that the bees groomed the pink off of her, and you got me thinking, but I can't see that it would be because of the color. Their entire world is full of color everyday when they go out into gardens, pink flowers everywhere. The bees aren't aware of that color chart, that is for beekeepers records.