Re: Introducing face in comments for various modes

[Christopher Dimech <dimech@gmx.com>]

> Sent: Tuesday, December 13, 2022 at 5:44 AM
> From: "Stefan Monnier" <monnier@iro.umontreal.ca>
> To: "Yuri Khan" <yuri.v.khan@gmail.com>
> Cc: "Thibaut Verron" <thibaut.verron@gmail.com>, "Heime" <heimeborgia@protonmail.com>, help-gnu-emacs@gnu.org
> Subject: Re: Introducing face in comments for various modes
>
> > Heime has a point. The complaint is not about *readability* of
> > modus-vivendi’s colors against the background. It is about
> > *distinction* between levels of Org headings, i.e. ability to
> > distinguish a level 3 heading from a level 4 just by color.
> 
> AFAIK relying colors to express the heading level would be a mistake.

How is that conclusion reached?

> > As far as I can tell, WCAG does not give any guidance as to
> > distinction between foreground colors, except for “thou shalt not make
> > the user rely solely on color”.

Colour would be an additional capability that one could use.  I do not see
how it will subtract, it will only add.  It is proper to assert that the use 
of colour only is not sufficient for distinction (other considerations include
font type, text size, text weight).  Having worked in remote sensing development,
an essential ingredient in most remote sensing images is color.  

While variations in black and white imagery can be very informative, the number
of different gray tones that the eye can separate is limited to about 20 to 30
steps on a contrast scale.  On the other hand, the eye can distinguish many more 
color tints, enabling small variations within the target materials or classes to
be discerned.  Colour is capable of provide expanded information.  It would be 
ridiculous to discount the use of colour.

 

> I think that guidance is quite apt here :-)
> 
> 
>         Stefan
> 
> 
>