Here is a link to a posting for a step by step tutorial describing setting up a Maya Linear Light Workflow.
Since version 2011 Maya color management has vastly improved. This tutorial uses these new tools and shows how to seamlessly match specific RGB color values while still working in a linear light workflow.
Included are sample Maya2012 and Maya2013 scenes.
It is focused on the Caustic Visualizer renderer but it's also applicable to mental ray.