While we assume that all oranges are orange in color because of their name, the fruit is often green when ripe, thanks to plenty of chlorophyll. In South America and other tropical locales, oranges are green year round. But in the U.S., where it's colder, oranges lose their chlorophyll and take on the color that matches their name. And because North American shoppers are used to oranges that are actually orange, imported fruit is either exposed to ethylene gas or shocked with cold water in order to remove the chlorophyll.