Color contrast: the #777777 grey

[afercia]

Even after the admin colors were updated with the new ones in #31234, there are still some occurrences of the #777777 grey. When used on a white background, ​the resulting contrast ratio is... 4.48:1 :) Should be 4.5:1.
Of course I'd agree it's a very subtle difference and the requirement is substantially respected but since there's the new #72777c grey available, why not just replace it?

On darker backgrounds, like for example for the "about text" in the About/Credits/Freedoms screens and in the footer, it should be replaced with a darker grey.

The login screen and the TinyMCE icons have their own tickets, I'd propose to make a patch to take care of all the other occurrences of #777777.

[afercia]

First pass, removes all the residual occurrences of #777 except for the login screen and TinyMCE.

[joedolson]

Given the scope of options available for using #777777 at WCAG AA, this seems like a must-have to me.

​https://www.joedolson.com/tools/color-contrast-tester.php?pass=true&color=%23777777&granularity=15

[afercia]

Replying to joedolson:
As far as I know, it's mostly (exclusively?) used on white or light grey backgrounds, not on grey backgrounds. Am I missing something?

[afercia]

Updated patch with ​the new "dark medium gray" from Hugo Baeta.

[michaelarestad]

This looks great. Nice update. Merge it!

[afercia]

In 36396:

Accessibility: Improve the color contrast ratio replacing the residual occurrences of the #777 gray.

Uses the existing #72777c on white backgrounds and the new #555d66 "dark medium gray" on darker backgrounds.

Fixes #35605.