I have a couple of suggestions for a better RoR coding experience. First, instead of using Sublime's default Ruby syntax, I'd suggest installing the Ruby on Rails TextMate bundle to get several Rails-specific syntax highlighting definitions that have additional scopes. To install, switch to your Packages directory on the command line (in Sublime, select Preferences -> Browse Packages... to find the directory on your system), then run
git clone https://github.com/drnic/ruby-on-rails-tmbundle.git "Ruby on Rails"
Next, instead of using the Railscast color scheme, you may want to check out the Neon Color Scheme (full disclosure: I'm the maintainer), available via Package Control. Neon, unlike many other color schemes, has many specific rules for a number of different languages, including Ruby and RoR. As an example, here's the code from Mike Slutsky's answer using Railscast:

and the same code with Neon:

Of course, it's completely up to you which one you use, and some people get distracted by having too many different colors on the screen, but I find my understanding of code (either mine that I haven't looked at in a while, or that written by other people) is improved with more highly-specific highlighting. YMMV, of course.