This article has a good reason for why people of color were not included in Atwood's book. Yet it's hard to imagine the book being successful if it were written not to offend racial sensitivities. And then written not offend other groups who might be offended about not being included.

I haven't watched much of the series, but as one commentator suggested, the inclusion of non-white characters amounts to "I have a black friend." If so, it really does not move the story forward.