Wow, and thanks to all who responded. I never knew that about the different genes for coat color, true black color, etc... I have heard about the color enhancing shampoos and may give those a try. Interestingly enough, I recently moved this black horse (along with his buddies) to a beautiful 5 acre pasture I have leased (I just lucked out and am totally grateful) and his coat is looking darker! Someone mentioned in one of the responses about food and water quality. Where I had him (and the others) boarded, the place was really nice but often the water tank out in the pasture was really gross. I had complained and they cleaned it up a little but not the way I would of. My hay was also not as good as the year before...(timothy grass mix) although I did supplement their hay with oats and vitamins (horse guard). The pasture at the boarding stable was dust and weeds mostly - now they are in beautiful grass, many varieties, and lots of tree coverage, streams, etc... (and I have cross-fenced to prevent over-eating). Age probably does play a factor...I hadn't considered that and he used to be a lot darker in the summer when he was younger. Oh well, I will be comforted by the aptly stated title of Mark Rashid's book ... "A good horse is never a bad color" and enjoy my nice horse whether he's black, brown, dun or somewhere in between (and maybe try some of those other suggestions)! Thanks to all.