Hmm.. what's all the fuss about this time. People don't find his skin tone dark enough for the part? My Chilean/Argentinian friends are as pale as he is in winter. After a few days in the sun in summer, they get a killer sun tan.

He shouldn't have any problem pulling off a visually credible Martell Prince.

Of course as long as he won't be in character (costume, but also attitude and body language) he doesn't look that much like the Red Viper.