This is ignoring the fact that Frozen is based on a Danish fairy tale (which I forgot its name. Was it The Ice Queen? The Snow Queen?) and there is no white-washing involved. No only where there no African peoples in Denmark at the time of its settings (like there are no non-whites in Brave and no non-Chinese people in Mulan), having a Black princess like in The Princess and the Frog (whose settling was in New Orleans, Louisiana, foreign to the original and conventional settings) would be impractical in this setting since Blacks cannot handle colder climates as easily as we Whites and even Asians.
Fans of the Disney Canon (and even "Non-canon", since the Walt Disney Company refuses to remember the failures of films like The Black Cauldron, Atlantis: The Lost Empire and Treasure Planet) are seriously getting worked up over another "White" Princess, when she is once again from Denmark a damn long time ago? And in a climate where the sun doesn't shine as often and its usually cold?
Also, nice watermark, whoever edited the image to adjust to a bunch of insipid complaints.