Colored Lights on a Light/Shadow Only Shader

Welp. This is the last problem I've been having with lighting in my game...

The following shader is what I use to make geometry "invisible", but still take light and shadows. It works, but only partially: colored light sources still appear as white on the surface, and they don't vary according to intensity of the light (unless the intensity is 0).

I will love you forever if you can fix it. And maybe I can send you a free copy of the game when it's done, I don't know if that's allowed. >.>

Here's the Unity shader code:

 Shader "Custom/Matte Shadow" {
      
     Properties {
         _Color ("Main Color", Color) = (1,1,1,1)
         _MainTex ("Base (RGB) Trans (A)", 2D) = "white" {}
         _Cutoff ("Alpha cutoff", Range(0,1)) = 0.5
     }
      
     SubShader {
         Tags {"Queue"="AlphaTest" "RenderType"="TransparentCutout"}
         LOD 200
         Blend Zero SrcColor
         Offset 0, -1
      
     CGPROGRAM
      
     #pragma surface surf ShadowOnly alphatest:_Cutoff fullforwardshadows
           
     fixed4 _Color;
      
     struct Input {
         float2 uv_MainTex;
     };
      
     inline fixed4 LightingShadowOnly (SurfaceOutput s, fixed3 lightDir, fixed atten) {
         fixed4 c;
         
         c.rgb = s.Albedo*atten;
         c.a = s.Alpha;
         return c;
     }
      
     void surf (Input IN, inout SurfaceOutput o) {
         fixed4 c = _Color;
         o.Albedo = c.rgb;
         o.Alpha = 1.0f;
     }
     ENDCG
     }
     Fallback "Transparent/Cutout/VertexLit"
 }