How DNA can reveal the eye and hair color of the longtime dead

Years of scientific research could finally put to rest an important question: What color was George Washington's hair, really?

Scientists from the Netherlands and Poland have come up with a new system that uses DNA samples to determine the hair and eye color of the deceased. The technique is called HIrisPlex, and it uses 24 different points in the human genome to determine what someone looked like long after their bodies have decomposed. In this case, it was used to accurately figure out the hair and eye color of a long-dead Polish war hero. LiveScience explains:

The system isn't perfect. Researchers say it can determine blue or brown eyes with about 94 percent accuracy. Hair color, on the other hand, is trickier territory: The technique can establish blond hair with an accuracy rate of 69.5 percent; brown hair, 78.5 percent; red, 80 percent; and black, 87.5 percent.

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The age of the DNA sample matters too. Genetic information unravels as it ages, which is why the further back in time you go, the less accurate a reading you're likely to get.

"This system can be used to solve historical controversies where color photographs or other records are missing," geneticist Wojciech Forensics tells LiveScience. But the technique has perfectly valid modern day applications as well. The system can be used to identify the hair and eye colors in forensics cases, for example, especially when the body is beyond recognition. Let's hope SVU's producers are taking notes.