So to avoid any surprises when you give birth, couples are now being offered DNA tests to check if they are going to pass on red hair to their off-spring.
The simple test, from the Who Do You Think You Are? Live exhibition at Olympia in London in February, will be able to tell you just that.
© Rex Features
Dr Jim Wilson, chief scientist at the company behind the test, said: "Through a simple saliva test to determine deep ancestry, we can also identify whether an individual is a carrier of any of the three common red-head variants in the gene MCIR.
"This means that families can carry a variant for generations, and when one carrier has children with another carrier, a red-headed baby can appear seemingly out of nowehere."
Recent studies have hinted that millions of Brits are carriers of the red-headed gene, which means that although they may have a different colour hair, they may be exposed to an increased number of health risks like skin cancer, Parkinson's disease and sensitivity to pain.
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