bake a colour to rhino for export to sketchup

I'm trying to find a way to bake colours onto a mesh so I can export to Sketchup.

The reason I want to do this is so that:

-clients can give me a sketchup model

-I make an analysis of the model where results are presented as colours onto the model

-I then export to sketchup

-I return the sketchup model to the client which is their sketchup model with revised colours showing the results

I assume the answer is to bake the colours (10 for example) to rhino materials and export as a 3ds. But I'm stuck. Can anyone suggest a method?