For example use the remapHSV node. And use for max output a value higher than one. Use a simple geo first with a strong backlight. And turn on the IPR to see whats happening in the render.
Well no, what do you mean with "range node"? If I pute a value above 1, when i put the map it's become one and lock. Radius map needs me to set different values inside the same geometry. I don't wanna relate only with shape or thickness of my geometry, because some parte are more distant, for example, from the bones…