I honestly assumed that there was little sunlight in the realm and thus there was little pigmentation. The only meaning that can be added to the story with more pigment is hotter apparent climates. If this world was all of the same pigmentation, we would still have race issues, we would just find a different way to differentiate the races.
Ex: Paridians despise Tarthans, which can be clearly recognized by their scraggly hair and tattoos. See, no color difference required.
This is actually quite interesting. If the entire continent was under the same climate, then its quite possible that all races/cultures of the Human species in that area would have the same pigmentation.
Assuming, of course, that there was no source of migration between the continents. (or that there were humans on any of the other continents).
Assuming homogenous climate and Isolated continent, it is quite possible that all human races in that environment would be of the same pigmentation. And if there is a distinct lack of sunlight, then it would make sense for them to be something similar to the Caucasians of earth.