Re: Diff mode faces

[Juri Linkov]

>     According to this classification, yellow is a dark color,
>     as it were suitable as a foreground color for light backgrounds.
>
> I think that is a non-issue.  Emacs never chooses foreground colors
> based on such a classification.  The only thing Eacs does based on
> this classification is to set the background mode.  So this
> classification has no relevance for anything else.

Sorry, I mixed foreground and background.  That sentence should read
as follows:

    According to this classification, yellow is a dark color, as
    suitable background color for a light foreground color.

>     OTOH, the formula I proposed in January produces the same
>     classification on TTY, xterm and X as:
>
>     Dark:  black red green blue magenta
>     Light: yellow cyan white
>
> Could you propose it again now?

(let ((bg-color-values (x-color-values bg-color))
      (white-values (x-color-values "white")))
  (>= (+ (* (nth 0 bg-color-values) 0.30)
         (* (nth 1 bg-color-values) 0.59)
         (* (nth 2 bg-color-values) 0.11))
      (* (+ (* (nth 0 white-values) 0.30)
            (* (nth 1 white-values) 0.59)
            (* (nth 2 white-values) 0.11))
         .6)))

-- 
Juri Linkov
http://www.jurta.org/emacs/