According to the symptoms in your question (swollen, painful and discolored feet) and the pre-existing condition (peripheral vascular disease,) you could be experiencing chronic venous failure of the legs. You'll need a physical examination and a Doppler-ultrasound examination to evaluate the local circulation and to identify the exact location of possible circulatory failure.
Wearing compressive bandages or elastic socks is very important for treatment of venous circulatory failure. Compressive bandages, however, are contraindicated in cases of additional arterial circulatory failure of the legs. A massage with gel that contains heparin in the direction of the venous circulation is also helpful. Treatment of chronic peripheral venous failure is a complex problem and you'll need to consult a specialist for vascular diseases.