I sprained by ankle 5 days ago. the swelling is almost gone and i started going to work today. the area below the ankle has turned purple though?

Bruising normal: The purple is bleeding beneath the skin... Bruising. It's normal to have a lot of bruising after a severe sprain. If you have pain along any of the bones i would see a podiatrist or orthopedic surgeon to make sure you have no fractures.

Eccyhmosis: It's possible you have a little eccyhmosis or bruising from your injury. It can occur anywhere from day 1 to 7.