[GRASSLIST:5095] colored area map question

[Ed Davison]

I have a map of the US with the states as areas in a grass vector map layer.

I need to be able to color these states based upon some sort of criteria, 
like number of requests from each state or population.  The criteria would
be scaled and each breakdown would be given a color, e.g. from 1-10 = green,
from 11-20 = yellow, from 21-30 = red, etc.  Or even a ramp from one color
to another across the range.

I cannot seem to be able to find anything like this.

Does anyone know how this would be done?

Ed