My first horse was a flea-bitten gray QH mare; at 15 she was mostly white. I loved her sooo much and she was so beautiful. And I adore grays.
The one sad thing about grays, and I haven't seen it mentioned in this thread, is that they have a predisposition to "gray cancer." It doesn't matter what breed, either. I know first hand about this horrible disease because at around 20 I found small lumps under her tail, and when she came my vet found more in her mouth. She told me that it could stay just like it was forever, or metastasize at any time. At 25, after retirement, she started dropping weight in late summer (and oh! What a pig was she!!), she ate constantly but within 3 or 4 weeks was racked out. I called the vet to put her down, but she died in the night before the vet came. My dad (she was at his farm) dug a hole and had her buried before I had to see her like that. But, not all grays get it, which is the wonderful part!!
"Bread may feed my body, but my horses feed my soul." ~~anonymous