I have Renaud's Syndrome, try riding with all white fingers!
Try Held Gloves,, I went with this glove to help out my freak condition. They have a space age material that they use that emulates whatever temperature that is introduced to it. So if hot, they stay hot, if cold, they stay cold. The problem I have noticed however, is that when my fingers are placed into the glove cold,, I can never get them warmed up because of the nature of the material. So, before I swing my leg over the bike, I run my fingers under hot-to-warm water, dry off, put on my glove liners,, then put my Held Gloves(pre-ride dryer sessions are sometimes warranted before).
Crazy, I know. But it helps this crazy condition. It's weird. I only lose circulation on the tips of my fingers when I ride my bike. No other time.