Hello, i want to know about a blue purple coloring of skin around heel and a bit upwards on the leg on both legs.

Bleeding in to skin: It sounds like you might have had a small hemorrhage in to the skin. This might be due to some form of trauma such as long distant running or even a slight pulled muscle. If continues to spread or worsen , would see a dermatologist for eval and poss tx. If some blood is trapped under your skin, it might take a while to clear.