Reading the books, I never imagined someone who looks like Jennifer Lawrence (even after dying her hair and applying bronzer) as Katniss. But I'll admit that Katniss' race was blurry and ambiguous and if I didn't know that the casting call for Katniss explicitly asked for a caucasian I wouldn't care that much, considering that Jennifer Lawrence is a great actress. [I wouldn't mind if they were open to all races and just settled on JL since they liked her acting best, as opposed to only looking at caucasian actresses to fill the part]

However, the Rue thing is flat out ridiculous. The book explicitly states that Rue has dark brown skin, and probably more than once at that. It boggles the mind how someone could be a fan of the books and be surprised that Rue is not white. Really! My mind is boggled. You have to have a brain that actively selects and deletes information that you don't like as you're processing it.