SyntaxHighlightingThemes/CLion/README.md

You must create a RailsCasts theme inside CLion first. Do this in Settings > Editor > Colors & Fonts, select any existing scheme and click "Save As" and name the new scheme RailsCasts

Close CLion, then go to ~/Library/Preferences/clion10/colors and there should be a RailsCasts.icls file which can be replaced with this one.

Note:

This theme is basically just a copy of the IntelliJ theme which was imported into CLion and then the C/C++ colors customized where needed.