Colour changes in a youngster - winter coat

[Ibex]

I found my youngster's sale photo the other day, taken sometime in the winter/early spring before she turned three. Photo clearly shows a darker bay horse with a mealy muzzle. By the time I saw her it was June, and she was a much lighter colour. I assumed it was just the difference between the two coats.

This past winter (3/4 yo) she grew a very RED winter coat - not even remotely dark, although her muzzle was a more mealy colour. Her summer colour is the same this year as last - a bright coppery bay, with faded legs.

So question... is this even possible for a horse to have a winter coat that's radically different from one year to the next?? The photo looks like her, but I'm wondering if it's actually a picture of her full sister who is a darker bay...

It doesn't matter... I bought the horse after meeting/riding her... I'm just curious about the colour!

[JB]

Yes, very possible :)

My OTTB mare came to me quite under-fed/nourished, and her coat was quite dark and dull looking. She was coming-4 at the time.

Now, 3 Winters later (this will be her 4th), her coat has consistently been a good bit more red - she looks like a bay in the Winter, whereas her first Winter here she looked like a very dark brown (what some might have called black-bay)