Before I vinyl-sided the house, I bought a 60lb pack of about 18-24 shingles from Home Depot. I only remember seeing white because that's what I needed. I guess if that's all they have, you can paint them.
My best to ya and hope this helps.
PS: You may try a national retailer called Bass Supply. Check around if you don't see them in your local Yellow Pages. It may be a bit of a drive ...