There are more than 50 varieties of avocado with colorful names like Pinkerton, Bogdon, Bacon, and Gwen (via Fine Dining Lovers). Not all of these varieties will darken as they mature, as the California Avocado Commission explains.
The two most common varieties in the world are Fuerte and Hass. The skin of a Hass avocado often turns dark green when ripe, but Fuertes are known to retain their lighter color. So while color can be an indicator of freshness, it’s best to check which variety you’re looking at before overlooking a display of Fuertes because none of them “looked ripe.”
The Hass avocado is actually a relatively new variety of avocado that is only about 100 years old. It may seem ancient to some, but it’s nothing compared to other varieties of avocado that date back thousands of years in Central and South America, with the first domesticated avocado tree said to have been planted around 5,000 years (via Avocados from Mexico).
The Hass avocado (which accounts for 90% of all avocados grown in California) rose to prominence in the United States during the first half of the 20th century, thanks to its sustainability and nutritional benefits.