when you first load the ramp you will have blue, red and green but change the colours of the ramp to roughly the same as the candle, much lighter actually, and put black on the bottom, you can key this node to animate it so it moves about with the 'flame' or whatever you need.
adjust the ramp, move it about, you will get the feel.
resolution messed up again, next post...
take it easy and life will be easy