My toes on one foot turn purple while sitting. i don't have diabetes & according to us doppler, my circulation is fine. any ideas what this could be?

purple toes: Althought the arterial side my be fine it sounds like there is reflux form the venous system. It is difficult to say without an exam exactly what this is. See your podiatrist for a more definitive answer. Good luck.

Listen to your body: If you have high blood pressure there is an imbalance in your autonomic nervous system. When the color is purple do the toes feel cold? If cold there is spasm in the arterioles (raynaud's phenomenon). See discussion in wikipedia.