Cyanosis

Cyanosis is a bluish or purplish discoloration of the skin, mucus membranes, or nail beds. It indicates a high blood concentration of reduced (deoxygenated) hemoglobin.

In the right photo, notice also clubbing.  This is an associated condition which affects fingers and toes and is characterized by proliferation of distal tissues, especially the nail-beds. This results in a broadening of the extremities of the digits. Note that the nails are abnormally curved and shiny.