some blacks are more 'stable' than others, the Kona Black is a pretty good black that holds it's darkness well. Black is one of the most difficult (colors) to dye...very hard to get a true black and when you do you never know for how long. everything can have an effect, from sunlight, heat, detergents, lots of variables. but the kona black is a very good one, with very little fading or color runs.