Cyanosis is the bluish discoloration of the skin due to inadequate oxygenation of the blood; its presence implies that there are deoxygenated hemoglobins in the blood vessels, thus turning the color...
When hemoglobin is poorly oxygenated, both the blood and the skin of Caucasians appear blue.It means a blue tinge to your skin, mainly your mucous membranes like your lips and under your mouth/tongue...