I noticed on my mare tonight when taking photos for her foaling thread that she had some distinct white hairs, almost a small patch, just above her tail. Could this be some kind of roaning or graying? She's currently 6 years old and this is the only place I've noticed this happening... photos below:
Entire mare, notice all white areas have fairly straight lines and cut-off points, no roaning on edges and no graying elsewhere.
White areas on her rump/tail area: