Hi Chuck and welcome to CentiLeo forum!
Ramp node is needed to create colored output for black/white Input Texture. For example, you may attach some CentiLeo Noise shader to the "Input Texture" slot of Ramp and then create green, blue, red, yellow, etc knots in the Gradient field of Ramp. You may also add Random shader (uniformly distributed greyscale colors) to the Input Texture of Ramp and create colored knots of Gradient to determine how frequent is red, how frequent is blue, etc. in the variety of objects with attached Ramp + Random shader.
You may also add Fallof shader to the Input Texture of Ramp and make colored knots. This way there will be color variations depeding on the view angle.

Kirill