Bruise is an area of skin discoloration caused by the escape of blood from ruptured underlying vessels following injury. Initially, they are red or pink then gradually becomes bluish and then greenish yellow. To get ride of early, draw off blood through a needle from the bruise site.
You can do the needle thing mentioned by rayoflight, but also make sure to put sunscreen on it everyday so it doesn't get sunburnt. It will stay longer if it does.