Chloë Grace Moretz has been tapped to play the titular role of the live action adaptation of "The Little Mermaid" but not everyone was happy when she revealed that she will be keeping her blonde locks for the role and for a very good reason: it's not a Disney adaptation. Universal Studios is taking charge of the film so hair color should really not be an issue at all since the red-haired mermaid is Disney's original design.
Chloë Grace Moretz already gave the most obvious reason why the little mermaid's hair is blonde and it's because the production is adapting the original Hans Christen Andersen story, which is also the story Disney's adaptation is loosely based on. The loose adaptation is emphasized because Disney also deviated from the original Andersen story.
The story of "The Little Mermaid" has been adapted time and again and, while Disney's red-haired Ariel is the most popular of all, the hair of the youngest mermaid princess whom Disney named "Ariel" was never canonically ginger. The only undersea creature whose hair color was mentioned was the little mermaid's grandmother whose hair has already turned white.
"[The] youngest was the most beautiful of them all. Her skin was as soft and tender as a rose petal, and her eyes were as blue as the deep sea, but like all the others she had no feet," Andersen describes his version of the Little Mermaid and, as you can read, there was never any mention of red hair.
"The color of Ariel's hair was a point of contention amongst the team. The red was chosen in part because red and green are complementary colors, and also because Daryl Hannah had just played a blonde mermaid in the very popular 'Splash,'" Disney explains in its blog. This only further proves that Ariel's red hair is only canon in Disney but not as the Little Mermaid.
This is why instead of rejecting the idea of a blonde mermaid outright before the cast and crew even begin production, why not give the Andersen tale a chance? It could be interesting how Chloë Grace Moretz would protray her version of "The Little Mermaid."
