Here's an example. Say you wanted a mountain to go from sand, to green, to brown, to white as you moved up it's elevation. You could use the color gradient to do this. Here's I've used the Elevation shader to go from black to white along the Z axis of the mountain. Next I used the color gradient to transform that black to white gradient to sand, green, brown, and then white.

Does that help?

Regards,
Eric Winemiller
Digital Carvers Guild
Carrara Plug-ins

Eric Winemiller
Digital Carvers Guild
Carrara and LightWave plug-ins