My Wife's Left Inside Ankle Below The Bone Is Bluish.

My wife's left inside ankle below the bone is bluish. She hasn't done anything that she can remember, but said it doesn't hurt. She did state that just above the ankle on the shin bone is sensitive. She usually walks a couple of miles a few times a week, but with the cold weather hasn't been able to. She was going to give it a few days, but I know she won't do anything