In a range of possible natural colors for hair, dark colors are the most common: more than 90% of people around the world have brown or black hair. This is followed by blonde hair.
Red hair, which occurs in only 1 to 2 percent of the
population, is the least common. Blue eyes are equally uncommon and may become more scarce.
One study found that between 1899 and 1905, more than half of white non-Hispanic people in the United States had blue eyes. But from 1936 to 1951, this number fell to 33.8 percent. Today, it is estimated that around 17% of people around the world have blue eyes.
The color of your hair and the color of your eyes descend to the genes you inherit from your parents. If there is a person who has red hair and blue eyes, there is a good possibility for one or both parents as well, but not always.
You must inherit two sets of genetic information for the color of your hair and the color of your eyes to obtain less common properties. The likelihood of this happening is rare, especially if neither of your parents has red hair or blue eyes. But sometimes the genetic stars are aligned, and people are born with a rare combination of red hair and blue eyes.
How someone gets red and blue hair