We've had Legacy for just over 2 years(got him in the beginning of June 2010). Today I was out in the pasture and noticed the black markings(not spots but now socks or stockings either, not sure how to explain them) seem to be getting lighter. I brought up a picture on my phone and they clearly looked darker when we first got him. What is causing them to get lighter? The vet guessed him to be in his late teens to early 20's and his previous owners confirmed this estimate when they contacted me. I have a few pics to explain what I mean, The first pic is one his previous owner sent me, it's probably from 3-4 years ago.
The next 2 are both from the fall of 2010
And this one is from last week.