After angiography some times a little leak of blood from the puncture site may produce discoloration of the skin and collection of blood which is called haematoma. This is not an unusual event and can occur in a fair number of patients. I think if you give time, this clot will get dissolved automatically and everything will return to normal and no other form of treatment is generally required. However, if the swelling increases in size or the bluish discoloration spreads further then you may require further treatment which can only be decided on direct clinical examination.