pidgin/nest

c1fbb1f6b8e5
WCAG 2 fixes for contrast and empty header

Testing Done:
Ran WAVE tool browser extension. They have a no-install, web version at https://wave.webaim.org/

As an example, improvement goes from 3+24 errors to 2+0 errors on https://pidgin.im/contact/

The colors are directly-scaled, viable suggestions, but it would be possible to make the green more green by exchanging red/blue for green while maintaining the same level of contrast. As an example #0c8a0c might be a bit more vibrant green. Please let me know if you would like me to suggest other slight color variations.

Bugs closed: NEST-45

Reviewed at https://reviews.imfreedom.org/r/777/
Alan Hoskins <alanhoskins@gmail.com>
Elliott Sales de Andrade <quantum.analyst@gmail.com>
Frederick F. Kautz IV <fkautz@alumni.cmu.edu>
Gary Kramlich <grim@reaperworld.com>
Harrison <harrisonhopkins@gmail.com>
Jason Allan <code@jasonderrythomas.com>
John Bailey <rekkanoryo@rekkanoryo.org>
Richard Laager <rlaager@wiktel.com>
Robert Vehse <robertvehse@fastmail.fm>
Sorvival <sorvival@tutanota.com>
Zero <programmingzero@gmail.com>