Custom Color Pass Use Transparency new Feature

In the new Custom Color Pass we can use Transparency new Feature to be added in the render pass
This feature works nicely when the Shader is plugged into color. but what if you want a different color than original one.

The problem is that the writeToColorBuffer shader expects its color input to be pre-multiplied (effect of transparency already applied), the workaround is to use a multiply node to multiply the custom color by the outMatteOpacity of the main shader. 

   

The “use Transparency” option on the render pass does not actually apply the transparency to the surface color, it just determines whether objects behind the surface are visible in the case where the surface is transparent.

 

Thanks to Justin Novosad for his feedback