This page shows how to create a sub-theme using drush to quickly get started with a custom theme on top of the Omega base theme.
Drupal provides a theme inheritance capability that lets you create sub-themes which inherit all the properties of a base theme with the exception of those that you choose to override. Since Omega is a base theme there is no reason to hack or edit it directly.
Before you begin, you must have drush installed and configured. For more information, see Specific instructions for installing Drush on different platforms.
Omega, ships with two commands for generating a subtheme. One is a wizard, and the other creates the subtheme in one go. It is always suggested to use the wizard as it does not require you to remember the syntax for specifying the desired options. However, if you want to write a script that, among other things, generates the subtheme for you on the fly you might prefer the direct command.
Creating a subtheme with the wizard is as easy as drilling into your Drupal directory in terminal, and typing the following command and answering the questions asked by the wizard:
drush omega-wizard