And this further exemplifies the problem -- why would you cast a light-skinned Iranian to play as a darker-skinned Indian woman?
Shohreh-Aghdashloo.jpg
Or a lighter skinned Argentinian to play as a darker-skinned Brazilian?
In it's simplest form this is just another example of the old "paper bag" test -- if you are lighter than a "paper bag" then you are considered more 'acceptable' to the "mainstream".
Hollywood has a long history of seeking out lighter-skinned actors to portray people of color, and this is made even more apparent when they actually go out of their way to change the character from one race to another for the big screen.
And yes -- I apply the same logic when I see them change "white" characters to "black" characters. I understand that they are doing so primarily to address the issue of "diversity" but I think that they should just integrate more heroes of color into the films rather than "race-bending" characters that already exist (i.e. Falcon in the Avengers vs. Heimdall in Thor).