I wonder, though, if part of the point of the original post, was that white is seen as normal and not needing description and non-white as departing from the norm and needing to be described so that the reader knows in just what way it departs from the norm and how far.

I wonder what it would be like to read a story in which the default was black, and only the (handful of) white characters came in for elaboration about their skin tones.