First, I'd try Southwest Strings. They have a website. Then, next, Elderly Music. They have a website too. If all else fails, try using light oak or birch and carve your own. Have the Luthier finish shaping the peg and reaming/tapering the hole. DO NOT USE PINE. I have seen very light coloured friction pegs...think they were birch.

Or, just take one of your pegs off and try soaking it in a Clorox/water solution for a few days. IF it lightens up, be SURE to let it dry out completely before putting it back on the fiddle. You might sand it lightly with steel wool too, as water tends to raise the grain.