They are still pretty dark compared to the rest of Westeros and the Stony Dornishmen, but like JAG said this is HBO. Nina Gold the casting director was also the casting director of Rome. She couldn't even find a little more color even though they also had Egypt to work into the show.

Queenie is dead. That girl is black. She is dead.

We found out the witch hunter organization were the ones who blinded Cordelia in this episode when Hank was talking to his dad and the black guy. They did it to force Cordelia to rely more on Hank obviously as we saw it backfired.