How to add Vertex color to Emission color on this shader?

I have this shader that I have hacked together from ones I found "if you recognize the code, thankyou!"

 Shader "Game/Terrain" {
 Properties {
     _Color ("Main Color", Color) = (1,1,1,1)
     _SpecColor ("Spec Color", Color) = (1,1,1,0)
     _Emission ("Emmisive Color", Color) = (0,0,0,0)
     _Shininess ("Shininess", Range (0.01, 1)) = 0.7
     _MainTex ("Base (RGB) Trans (A)", 2D) = "white" {}
     _Cutoff ("Alpha cutoff", Range(0,1)) = 0.5
 }
 
 SubShader {
     ZWrite on
     Alphatest Greater [_Cutoff]
     Tags {"Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent"}
     Blend SrcAlpha OneMinusSrcAlpha 
     ColorMask RGB
     Pass {
         Material {
             Shininess [_Shininess]
             Specular [_SpecColor]
             Emission [_Emission]    
         }
         ColorMaterial AmbientAndDiffuse
         Lighting on
         SeparateSpecular on   
              
         SetTexture [_MainTex] {
             Combine texture * primary, texture * primary
         }
         SetTexture [_MainTex] {
             constantColor [_Color]
             Combine previous * constant DOUBLE, previous * constant
         }  
     } 
 }
 }

My Question is how would I change it so that the vertex color is added to the emission color, so that if I set the vertex color to red the objects glows red. The same way setting the emission color to red does now.

Thank you