I've used Solarized themes sometimes in my favorite editors (Vim, Emacs and RubyMine). I like it. Now I'm using Quiver, so why not use Solarized?
Unfortunately, Solarized themes didn't exist for Quiver. Fortunately, Quiver allows me to make custom theme, and Solarized makes its color scheme public, so why not create theme?
It was a really fun weekend project. I looked into how to use Solarized color scheme. When I read Solarized homepage, I was impressed by its principles very much. I also looked into how to make custom theme for Quiver. There was a great document How to Design a Custom Theme that helped me to understand the way. I also learned that how can I customize markdown cell's background (and so on) from built-in Spacegray theme (I could export it so I could read its settings).