RE: Face color changes

[Drew Adams]

    Is anything wrong with "M-x customize-face RET"?  It even has a
    convenient entry point from the buffer created by "M-x
    list-faces-display RET" (e.g., click mouse-2 on the face's name).

No, nothing wrong with it. Everything is right with it.

Some people are just loathe to customize, are intimidated by it, cannot
figure out how to start, or are too lazy to try. We should make it as easy
as possible, but there will always be some who don't get it.

Heuristics to deal with light and dark (and perhaps medium) backgrounds are
a real help in this regard: there is less to customize. Coming up with
heuristics that work well in more cases is not easy, but would be helpful.
In this regard, I think Juri is making a good start.