WCAG 2 fixes for contrast and empty header

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.