git clone git://github.com/DrMegahertz/pygments-style-railscasts.git
cd pygments-style-railscasts
python setup.py build
python setup.py install
>>> from pygments.formatters import HtmlFormatter
>>> HtmlFormatter(style='railscasts').style
<class 'pygments_style_railscasts.RailscastsStyle'>
pygmentize -S railscasts -f html > railscasts.css
Please read the official documentation for further information on the usage of pygment styles.