Howdy, Pards,
If it is NOT oil, and IS an alcohol-based dye, try Fiebing's Bag Kote. This is a water-based liquid, but it does the job on my holsters, especially black ones, which are the worst to stop rubbing off on everything! If it is oil-based, then I'd try the other recommendations, but then also try the Bag Kote. Tandy/Leather Factory does NOT handle Bag Kote, but does have Tan Kote, which is about the same thing, but tinted.
Hope this helps.