Prettify - Color unification

[ZumDeWald]

Story:
As a user I expect colors to match throughout the app and be accessible in both light & dark modes so that I can easily focus on the content without stylistic distractions

Details:

• Ensure colors match on each page and work in both light/dark modes
• Solidify a color for links and again make sure it works in light and dark mode

[jaytula]

I'll try to breakdown this one a bit. The Home Page and the Quiz List Page looks okay to me. Here are the items I came up with:

• Contribute Page (http://localhost:3000/contribute). The h3 header tags are flush against the edge of the page. Style and/or restructure HTML to improve look.
• About Page (http://localhost:3000/about) Color of Links in Dark Mode needs to be much lighter.

Let me know if I'm missing anything.