bug#6227: Color isearch regexp submatches differently

[Eli Zaretskii]

> From: Lars Ingebrigtsen <larsi@gnus.org>
> Date: Sat, 19 Sep 2020 23:29:48 +0200
> Cc: Lennart Borgman <lennart.borgman@gmail.com>, 6227@debbugs.gnu.org
> 
> I think the results are really nice.  I guess we should add a few more
> faces before applying?
> 
> Anybody else got any comments on this?

Comment #1: Do we really want to turn this feature on by default?

> +(defface isearch-1
> +  '((((class color) (min-colors 88) (background light))
> +     :background "magenta2" :foreground "lightskyblue1")
> +    (((class color) (min-colors 88) (background dark))
> +     :background "palevioletred3" :foreground "brown4"))
> +  "Used for displaying the first matching subexpression.")
> +
> +(defface isearch-2
> +  '((((class color) (min-colors 88) (background light))
> +     :background "magenta1" :foreground "lightskyblue1")
> +    (((class color) (min-colors 88) (background dark))
> +     :background "palevioletred4" :foreground "brown4"))
> +  "Used for displaying the second matching subexpression.")

Comment #2: This seems to effectively disable the feature on displays
that have fewer than 88 colors.  Is that intentional?  If so, why
doesn't the documentation say so?

Comment #3: What about NEWS and the manual?

Thanks.