In the “Game of Thrones” universe and the prequel “House of the Dragon” – season 1 of which just finished airing – members of the Targaryen family possess some distinguishing features. The most striking among these physical features is their silver or white hair. But, many viewers have wondered, why does every Targaryen have silver hair?

It is obvious that Targaryens anticipate their offspring having white or silver hair when they are born. In fact, Viserys and Alicent Hightower’s true-born children all inherited their father’s silver hair. Meanwhile, based only on their brown hair, Rhaenyra Targaryen’s children are assumed to be “not of pure Targaryen blood”.

What is it about the Targaryen silver hair? Can Targaryens have hair that is a different colour at birth? Based on George RR Martin’s books, the answer is not as simple as you may expect.

So, what really causes the Targaryens to have silver hair?

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The Targaryen family hails from Old Valyria, where lighter skin tones and hair colours were particularly common. As a result, the family had white or silvery blonde hair. The Targaryens have been able to keep their distinguishing Valyrian characteristics due to years of inbreeding.

George RR Martin might have given the Targaryens such an unusual hair colour out of the blue to set them apart from the Westerosi people and suggest a certain otherworldliness about the royal lineage, underscoring the idea that they do not really belong in the Seven Kingdoms.

But not every Targaryen has silver hair. In “Game of Thrones,” Jon Snow is a Targaryen, and his hair is dark. And he is not the only one. In George RR Martin’s books, characters with black hair include Baelor Breakspear and Aegor Rivers. All these instances include those who chose not to “keep it in the family.”

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Long story short, as per genetics, it is most likely because dark hair is a dominant gene in the real world and light hair is recessive. Targaryens in “Game of Thrones” and “House of the Dragon” who were not born through incest have darker hair, it seems. Therefore, it is less likely that offspring born to a single Targaryen parent will exhibit Valyrian characteristics, such as silver hair.