I have had a similar problem in the past with the same finger, but this is the most severe. Now you can actually see the difference between this finger and the rest of my fingers. Also, there has perhaps been a numbness, but the cold sensation is a new symptom. It is white, with blueness in the creases. It just started on Tuesday morning. The only thing I have done different with my hand is some lifting with my hand stretched out, but not with anything particularly heavy.