It's always been an interesting point of discussion, but the subject peaked of late due to the news that Chilean actor Pedro Pascal has been cast in the role of Oberyn Martell. The Martell family (who haven't yet appeared on the show) are described as dark-skinned in the books, and this had some readers up in arms, saying that the show had been whitewashed. Martin addressed the concerns at length on his blog:
I wasn't present for Pedro Pascal's audition, but I understand that he really killed it with his reading. And since his casting was announced, the producer of another TV show on which he appeared recently has written me to say how terrific Pascal is, and to congratulate us on the casting. So I suspect that he will turn out to be a wonderful Red Viper.
I do know that David and Dan and HBO do favor having a racially and ethnically diverse cast on the series. It is true that we've lost several black characters who appear in the novels (Chataya and Alayaya, Jalabhar Xho, Strong Belwas), but to balance that, characters like Salladhor Saan and Xaro Xhoan Daxos, both white in the books, have been played by black actors. Missandei as well, though in the books the Naathi are golden-skinned, not white.
When and if the show introduces Prince Oberyn's daughters, the Sand Snakes, I expect we will see the same diversity as in the books, ranging from Tyene (blond and blue-eyed) to Sarella (light brown skin, as her mother was a Summer Islander). And I expect that the crew of the CINNAMON WIND will all be cast with black actors... assuming, of course, that Sam's voyage remains in the story.
The discussion continues, and he goes on to address some of the more nuanced issues of race and even body image in the Game of Thrones universe. For our part, we think both the show and the books do a pretty good job of representing all sorts — though it's true that all of the main characters are white, if there's one work of contemporary fiction that loves to upturn the status quo, it's definitely GoT. (UpRoxx)