The numbness and blue color when exposed to cold sounds like something that occurs with Raynaud's phenomenon (also called Raynaud's disease or Raynaud's syndrome). You can read more about it here: What is Raynaud's?
A description of Raynaud's doesn't usually unclude swollen joints, though, so there may be something else going on. When I hear swollen joints, the first thing I think of is arthritis. Since Raynaud's can accompany arthritis, it's a possibility to consider.
The bottom line is you really need to see a doctor to get an accurate diagnosis. Swelling shouldn't be ignored as it may indicate inflammation or infection. Check with your doctor to find out exactly what is going on and if there is a treatment that can ease your discomfort.