Why are there no South Asian characters, and why don't any of the 'black' characters have kinky hair, and why is Tuon so notably dark of skin if her skin tone is common among Sea Folk, Andorans, Tairens, Taraboners, Altarans, Domani, Seanchan, Saldeans and Aiel (they are also described as 'dark')?

Errh. Sea folk are described as very dark, Domani coppery-skinned, Altarans olive-skinned, and Aiel sun-dark (but actually pale underneath their clothes). I don't recall Saldeans ever being described as dark, and Seanchan people are very varied in skin color (Tuon being very dark, Selucia creamy skinned for example). I don't really understand what you mean by "why is Tuon so notably dark of skin"... She's just black, I never perceived it as her being "notably" dark, that she stood out or anything. People in Randland have all different types of skin colors and that's just the way it is.

Oh, and btw, when Tuons hair was growing out, Mat described it as very tightly curled, which probably means she has "kinky hair"...

Along with Rahvin and all the Sea Folk.

 

Rahvin is never described as black, just dark, which is usually a very different thing.

I think it might have raised an eyebrow or two if he had waltzed into aemlyn, claiming to be fron Andor, while sporting a colour of skin only those who had met the Sea fold would have ever seen before...

Uhm, correct me if I'm wrong here, but as I remember it, when Rand and Mat first came to Caemlyn, the people were discribed as very varied, something about the skin colors ranging from "too dark" to "too pale".  After all, Caemlyn is one of the biggest cities, I don't think anyone would have raised an eyebrow at Rhavin just because he was black.