Hello, I have a 22 year old Arabian gelding that is changing color. I fed him Purina Healthy Edge Active Senior grain and 3rd cut local grass hay over the winter along with regular pasture grazing. He was blanketed all winter as well.. He has shed his winter coat and is considerably darker then he ever has been (the hairs almost look black or just a dark brown). Does anyone have an explanation for this? It seems to be an all over body thing not just here and there. I tried to search the internet but that was not much help lol. Is this common for older chestnuts or is it because of what I fed him? He is currently on a diet since he thought it was a good idea for him to over indulge himself on the new grass.