She really is lovely!
I'd be inclined to think a color balance issue, like maybe a filter! I'd say wait until you have her in hand, because dye would also be an option. I'd suggest looking for uneven spots, like the ear tips, edges of the hooves, the inside of the neck, places where the dye wouldn't take 100%, or might take 110%!
Also, if you pop her head off to look for dye evidence, you could look and see if her hair looks obviously rehaired! It's pretty clear that it is, but it's nice to confirm.