How long have you been on warfarin? There is a rare syndrome called purple toe syndrome that is related to warfarin, although it usually manifests itself very early in treatment (3-8 weeks after starting). You can read more about it here:

http://patientblog.clotconnect.org/2011/03/29/purple-toe-syndrome/

I have been on it for 6 months this week. I do wear compression thigh highs. I did not wear them for a few days this week. wondering if that could be reason I am getting cold feet and a purplish color to toes??

Very difficult to say. Few questions
1) Do you jave any associated pain?
2) Is it blue and purpe all over, or only limited to the veins e.g. spitder veins
3) is it triggered by some external factors, eg.. stress?, physical activity?, cold?

Generally, side effects of warfarin appear very early after treatment, so I doubt this is due to warfarin.

The most common reason for this sympotms is somehow circulatory. This could be caused by (1) decreased arterial flow to the toe , (2) impaired venous flow from the toe towards the leg and (3) abnormal circulating blood flow. As an example of 1) then atheroslerosis can cause hardening of the small arteries in the extremities (e.g. toes) and this results in less blood flow and the toe may become purple and feels cold, and there is often lots of pain. It is possible that taking of the compression stocking caused some imbalance in your circulation.

Another possibility is the Raynaud phenomenon or disease, that can cause this purplish colour and cold feet:
http://www.mayoclinic.org/diseases-conditions/raynauds-disease/basics/definition/con-20022916

I would recommend to let a doctor to have a look at your symptoms. The cause for this sympotms could be something relatively harmless or it can be signify something serious. There are large number of possible causes for your symptoms.