I Get Sun On My Feet, By Wearing Shorts While

I get sun on my feet, by wearing shorts while playing tennis - the right leg bet.the knee and ankle by the shin, I would think is the blood shown in the capillaries - this dark spot of the sun occurs in both legs, but the rt. leg is the one that is darker - and is seems to be spreding, making it less visible - what do u Rx? txsI believe, I have not been too explicatory -