What would cause an eyelid to go purple colour all over without any blow to the area -either around it?

Eye Shadow??: Usually purplish discoloration implies bloody extravasation probably secondary to trauma. You state there was no trauma. Could you have a blleding diathesis such as a hemophilia or a previously undetected von Willebrand's Disease. You should be seen by a flesh and blood doc, not a computer doc who can get a better history and physical exam from you.