Assigning different colors to different layers in one action ?

[zooropa]

I am importin a model with several layers from Rhino. I would like to assign a gradient of colors (Pick within a particular range of tones) to the model. Not manually pick one by one, but pick several colors and assign it random.

Is this possible ? I remember It could be possible in Modo. I do not remember the name of the material operation. Kind of Color ID or Random ID...
mmm