What Causes Stiff Legs With Pinkish Discoloration In 79-year Old?

My 79-year old father has very stiff legs with slight pinkish discoloration but no pain, along with swollen feet. He also has Parkinson's disease, no tremors, but poor balance and increasing difficulty in moving about. He uses a walker, is about 5'7" and weighs about 145. Also, he has congestive heart failure and a pacemaker. He does not currently take any arthritis medicine. What could these symptoms be, and what would be the best treatment?