What is the old default theme called and how do I select it?

The blue fonts on the index page are unreadable for me.

As is happening all over the web, web sites are being changed to accommodate mobile users. PC users are being left out.

I am trying to see if I can start a foundation that helps with maintaining accessibility to web sites for those of us with visual processing and other visual barriers. W3C is setting some standards with WCAG but they have no ability to press the issue with inaccessible web sites.

Between visual agnosias, aphantasias, and other visual challenges, many people are being shut out as formatting changes are made to serve the mobile users.