Earth & Sky

Kids: Can colorblind people see rainbows?

If you’ve ever seen a rainbow, then you’re familiar with ROY G. BIV — Red, Orange, Yellow, Green, Blue, Indigo, Violet.

But not all people can see all colors — some people were born with an inability to see certain colors. Most people with impaired color vision can see different colors – that’s why researchers prefer the term “color deficient” rather than “colorblind.” About 10% of all males in the U.S. are color-deficient, and about 0.5% of all females are color-deficient – that’s all color-deficiencies, not just red-green.

Color-deficient people can usually see rainbows, but that rainbow may seem to have fewer colors than rainbows seen by other people.

The cone cells in the eye are responsible for perceiving color. There are three different kinds of cones – those that absorb red, green, and blue light. The most common kind of color deficiency is a “red-green deficiency” – when a person can’t tell reds from greens.

That person might see only two colors in a rainbow – yellow and blue. That’s because all the medium-to-long light wavelengths – red, orange, yellow and green – blend together into just one color – what you or I might call yellow. A faint rainbow against a bright blue sky can become just a dim yellow stripe. Someone with severe color deficiencies might not see anything at all.