Cocktail grapefruits are medium to large fruits, averaging 7 to 10 centimeters in diameter, and have a round to ovate shape with a flattened bottom on the non-stem end. The peel is thin, smooth, lightly pocked with tiny oil glands, and transitions from green to yellow with maturity. It is important to note that some green may remain on the peel when ripe, and the green coloring is not an indication of ripeness. The skin is easy-to-peel, revealing a thin layer of bitter, sour white pith.