A grapefruit is ripe when it no longer has a green tint to its color and no longer smells like ripe fruit. When it comes to pink grapefruit that is perfectly ripened, the peel of the fruit has a light red or rosy appearance to it when it is in peak perfection.
As a grapefruit ripens, the antioxidant levels in the fruit increase, making it better for overall health. This fruit also has high levels of vitamin C in particular. Thus, it is important to find as ripe of a grapefruit as possible before eating it in order to take advantage of its full health benefits.