I've got one for you. My chestnut QH was pregnant when I bought her, no one knows who the sire was, breed, color, etc. And the baby she had, has been doing a rainbow fish type of color change throughout her life. When she was born, we thought buckskin. As she got older, we thought maybe she'd be buckskin with a blanket. Then it was bay. Then grulla, and now maybe roan? Hopefully someone here can settle the dispute. She's a little unique...as I've only found one horse online that looked similar to her coloring. So I'm posting pictures of her from pieces of her life so far, and maybe someone can finally solve the mystery of what color she is.
The day she was born
7 Months: That's not water, it's her fur
1 year (The middle of her side that grew back white-ish was shaved because her winter coat wasn't shedding and she was covered in sweat because it was far too warm outside)
1 year, 6 months (taken today)