Ah, you're a purple one! I get like this if I drink too much caffeine, take too much Adderall (amphetamine), and/or get sleep deprived. Do your hands and feet also sweat like crazy? It has been so concerning, I went to a vascular surgeon to see what was up. Much to my relief, he said I am fine. Pulse, oxymetry, perfusion, etc etc all of this is fine. He said, it's just intense vasoconstiction, mostly genetic in nature. He said I don't need to stop caffeine or Adderall or anything, just try to avoid prolonged exposure in cold (frostbite is maybe a bigger risk). Anyway, I have never had a problem. It just cosmetically looks a little freaky sometimes. Raynaud's, but also the more accurate term may actually be better defined as acrocyanosis. Google image search that. I recommend seeing a doc if you're concerned. Cheers