The broken wrist has hindered and blocked the normal blood flow and circulation to the fingers. Dead blood and dying blood are accumulating in the fingers, making the fingers purple.
Try to get rid of the purple in the fingers by soaking the fingers and hands and wrist in hot water. If the dying and dead blood that has accumulated in the fingers does not go away, go to the doctor immediately.
A broken wrist is an emergency. Go to the doctor to get the wrist fixed.