Increase color contrast throughout site

[Inkering]

Resolves #232

• Increase footer contrast by making non-link text black

[netlify[bot]]

Deploy preview for sfpc ready!

Built with commit c426343972140a3d885d9e835c65e7f896f76f17

https://deploy-preview-240--sfpc.netlify.app

[Inkering]

Tried to do an initial color choice that isn't entirely different from the existing teal one. Also changing the hover color.

[solon]

Thanks for this!