Let's say that the average quantity of carotenoid contained in 1 shrimp of weight 250g, is 2 milligrams. Therefore the pinkness of your skin would increase by an avarage of ~0.002%. So we would have: 60/0.002=30,000 shrimps to eat in order to arrive at a 60% of skin pinkness. 30,000*250g=7,500,000g=7,500Kg of shrimp to eat.

The answer is more or less 30,000 shrimps though