If there is bluish colour of a bruise, then the age of injury is

As red blood cells degrade within a bruise, haemoglobin breaks down into bilirubin and biliverdin, and it is these pigments that pass through a series of colour changes. These are generally from reds through to darker reds/ purples, through to yellows, browns and greens. Determining the Age of a Bruise by its Color Red (swollen, tender) 0-2 days Blue, Purple 2-5 days Green 5-7 days Yellow 7-10 days Brown 10-14 days No fuher evidence of bruising 2-4 weeks Ref : Krishnan vij Textbook of Forensic medicine and Toxicology 5th edtion ; pg no - 200