So, Carl Carlson, Dr. Hibbert and Bleeding Gums Murphy are pretty clearly Black, Apu is pretty clearly Indian, Bumble Bee man is pretty clearly Mexican, but all the yellow characters are... "a null race?"
Despite all clearly having signifiers of white people, and several of them clearly ethnically Italian or German, and most of the rest being Waspy?
Does this not simply speak of what you perceive as the "null race" or, perhaps, default race?
And when the Simpson's producers said a few years ago that they were going to stop voicing non-white characters with non-white actors, who did they find to voice all the "null-race" characters?
So the majority of people are yellow, and yet we still have black/brown characters (Bleeding Gums Murphy, Apu, Carl, Dr. Hibbert, etc) and most East Asian characters were given almond shaped eyes.
It's almost like there's a correspondence with the "average" yellow Simpson's character and some real world US ethnic majority...