@gettingnowherefaster for some reason the app wasn't letting me publish your submission, so I'm copy-pasting!
Hi! I just recently discovered your blog, so niche and interesting! I was wondering what you make of my dog? Parts of her coat are solid black, but on others the hairs are grey at the base and black at the tip. Some of her longer tail hairs will even have bands of black + tan/brown + white (agouti?). Thanks in advance :)
She is a lovely black tanpoint with minor white spotting!
ky/ky E/- at/- B/- D/- S/-
That variation in color is light undercoat and banded hairs. It's a common misconception that banded hairs mean agouti - in reality almost all of the A-Locus patterns (sable, agouti, saddle, and tanpoint) can have banded hairs. Light undercoat is probably genetic to some extent, but isn't testable. Some breeds, like Rottweilers, have selected strongly away from this trait, but in others (like rough/smooth collies) it's pretty common.