Aah, a new thread!
I really like the Biomes idea; also flowers ^^
As for my own input... how about... hm.
Gazelle or antelope quids? Some of those can have some pretty striping, which could make for an interesting Equid.
Big cats? i.e., tiger, snow leopard, cheetah, lion. I know you couldn't do spots, but a good basecoat and some creative quip could make a resemblance.
Moths and butterflies? There are some moths out there with som GORGEOUS wing patterns, even if butterflie's bright colours make an Equid hard to make. I could dig a moth Equid, though.
Lemurs? Gray base, perhaps with faint quipping, then white-and-black striped tail XD I can see some other pretty lemur species Equids running around, too.