http://cg.tutsplus.com/tutorials/autodesk-maya/creating-an-advanced-multi-character-rig-for-futuramas-bender-part-1/

In the third and final part of Shaun Keenan’s massive multi-character rigging series for Maya, you’ll continue adding additional features and functionality to Bender’s rig. Lessons include setting up color switching, adding additional assets to the rig and Bender’s body, and last but not least, creating the final switch controller. Shaun will also give you a full demonstration of his ghost rig setup to finish the series off.

Tutorial Part 2

Tutorial Part 3