After talking with my wife I now disagree with my self on this (but don't see how to remove the post) as it would be highly controversial and may seem racist even though the intention would be the opposite.

Having a diverse cast and yet having a distinctive look to each color, makes casting difficult. However, because this is essentially a story of slavery and racism I believe it would resonate better if the casting of colors conformed to racial stereotype and then the TV show or movie would show the Sons of Ares being a group that is trying to shatter these stereotypes.

As such, I think all of the high colors should be cast as white actors and the reds should be black actors but with red hair and eyes. Darrow should definitely be Michael B Jordan and with his transformation to gold he should be made to look white. I think that pinks should be South East Asian to reflect the sex tourism industry of Thailand and Vietnam. Obsidians need to be white because of the clear Viking connection. The rest should be made up of different races as long as each color is consistently cast.