Accessibility-wise it has problems. Font-size, colour, contrast to name a few. And overuse of bold. When everything has emphasis, nothing does.

And green? How did that get approved?

I'm glad things are still moving in the Ruby community. I use it every day. But Elixir is winning the mind-share battle over Ruby at $dayjob these days. And their documents is second to none. One of the best that I've used.