Raynaud's phenomenon?

technically, raynaud's phenomenon has discernible whitening, then blueing (both are hypoxic states) [numbness at this stage] then reddening (restoration of blood flow) [burning sensation said to occur at this stage] of the affected digits (fingers or toes).

however, in actuality, just whitening and numbness is needed for a high suspicion of raynaud's.

if it's not particularly troubling (or does not match the classic raynaud's description) you might ask a normal clinic doctor about it at any time for a more formal examination. the specialist of choice though would be a rheumatologist