I saw purple spots on the back of my toes and blue color between my toes as well.

See the podiatrist: If you are a runner, this could be be bruising from the toes hitting inside your shoes if you are a smoker, this could be localized blockage to the vessels in the feet that can become serious if you are noticing a coolness and the toes aren't blanching, this could mean loss of circulation and gangrene. Get checked by the podiatrist.