Have you ever taken a color vision test? These tests help identify color vision deficiency, usually an inherited condition. People with this condition struggle to distinguish certain colors—especially reds and greens or blues and yellows. There are four main types of color blindness, and many people don’t even realize they have one until a real-life situation—like being unsure of a traffic light’s color—reveals it.

True color blindness, where someone sees only black, white, and gray, is extremely rare. Most people with color vision deficiency can still see some colors, though not always accurately. Want to check your color vision? Try reading color-based words in these tests—only those with perfect color vision will read all eight words easily!

Interestingly, many color-blind people can still see blue well, since it’s processed by different receptors in the eye. Green, too, can sometimes be recognized, especially with help from environmental clues.