Need a better color scheme for coderay blocks

[jenweber]

It burns us, precious.

There are three background colors needed: standard, removed code, and added code. The end result should have accessible contrast between each color and with the text, which I suspect will also require changing the syntax highlighting.

Anyone who wants to help, consider starting with playing around in dev tools css and posting screenshots, as a first step, before opening PRs.

Maybe this is a candidate for ember-styleguide? @MelSumner what do you think?

[MelSumner]

@jenweber I'd like to resolve this in the styleguide and then create a new issue to implement that would be good for new contributors. Does that sound okay?

[jenweber]

@MelSumner sounds great! Feel free to close this or edit my post. I'll remove the labels for now