Re: Frame background mode

[Richard Stallman]

I don't agree with the new classification that your code does.
Several of the colors that it calls "light", I believe are dark.
For instance, light slate gray, cadet blue, dark sea green,
light sea green (!), and gray59 all seem like light colors to me.

I made the test by modifying list-colors-display to display the chosen
color in the background, with foregrounds of white and of black.  That
way I can compare the visibility of both white and black against this
background.  If black is more visible against it, it is a light color.
If white is more visible against it, it is a dark color.

This is with my screen gamma set to 1.5, since it is an LCD screen.
It could be that this LCD screen needs a different gamma value.
I don't know how to tell what is "correct".  (It is a Thinkpad T21.)

How about if you try this exercise on your screen, and tweak the
threshold and see if you can get good results?