Composite screen shader with transparency?

Hi everyone,

I am building a shader based off the the funky glow shader in the Shader Replacements asset sample. Everything is working really well except one part. Rendering the separately labelled render types with transparency. I have a sphere which is being rendered under the rendertype of metaball, and I added a quad with a custom unlit shader that renders a radial radient (white to transparent):

The combination script (reminiscent of RenderFunkyThinks.shader) looks like this:

 Shader "Hidden/RenderBulletShader" {
 
     // draw out items in plain color (untinted) that are
     // rendered with metaball tag.
     SubShader {
         Tags { "RenderType"="Metaball" }
         Pass {
             FOG { Mode Off }
             Color (1,1,1,1)
         }
     }
 
     // render out all other pixels as empty nothingness
     SubShader {
         Tags { "RenderType"="Opaque" }
         Pass {
             FOG { Mode Off }
             Color (0,0,0,0)
         }
     }
 }

I thought that the Color(1,1,1,1) was just a tinting function, but it turns out that it will turn all pixels rendered to that render type white. is there a way to retain the color/transparency?

Btw, running it now it looks like this (Not what I want):