Overriding Halo shader

Hi all

I'm trying to change the halo component appearance so that the gradient is a bit steeper toward the end, because I want it to be a halo around the edge of a sphere. Currently it's too weak. I hope that makes sense.

My current idea is to change the shader behind the Halo component. In the Unity docs they say grab the built in shaders from http://unity3d.com/unity/download/archive/ and simply put the overriding shader...

Overriding Halo shader