Emedinews:Insights on Medicolegal Issues:Post mortem discoloration does not have the same connotation as cyanosis produced during life

• A gravitational pooling of blood in the veins and capillary beds of the dependent parts of the body occurs as the body remains lying in a position and cessation of the circulation after death. Postmortem coloration helps the doctor to estimate the time since death.
• The skin of deceased may show dark purple discoloration due to accumulated blood. The process begins immediately after the circulation stops, and in a person dying slowly with circulatory failure, it may be pronounced very shortly after death.
• Postmortem lividity is first apparent about 20–30 minutes after death and is seen as dull red patches or blotches, which deepen in intensity and coalesce over the succeeding hours to form extensive areas. Lividity is present in all bodies, although it may be inconspicuous in some and thus escape notice.
• Postmortem lividity is usually well–marked in the earlobes and in the fingernail beds. In a supine corpse, there may be isolated areas of lividity over the front and sides of the neck resulting from incomplete emptying of superficial veins. If the head is slightly flexed on the neck, then lividity may have a linear distribution corresponding to the skin folds.
• Fading of the primary pattern of lividity and development of a secondary pattern of lividity will be quicker and more complete if the body is moved.
• Cyanide poisoning results in lividity, which has been described by different authors as pink, bright scarlet, and violet.