Add Main Color attribute to this shader please...

I found this Shader somewhere in the web. Thanks to the shader writer. But I don’t know how to add main color attribute to this shader…
Please some one can add main color attribute having alpha too… in this shader… Thanks !

Shader “Platogo/CurvedAlpha” {
Properties {
_MainTex (“Base (RGB)”, 2D) = “white” {}
_QOffset (“Offset”, Vector) = (0,0,0,0)
_Dist (“Distance”, Float) = 100.0
_Alpha (“Alpha”, Range(0.0,1.0)) = 1.0
}
SubShader {
Tags {“Queue”=“Transparent” “IgnoreProjector”=“True” “RenderType”=“Transparent”}
LOD 100

	ZWrite On
	Blend SrcAlpha OneMinusSrcAlpha 

	Pass
	{
		Lighting Off

		CGPROGRAM
		#pragma vertex vert
		#pragma fragment frag
		#include "UnityCG.cginc"

		sampler2D _MainTex;
		float4 _QOffset;
		float _Dist;
		float _Alpha;
		uniform float4 _MainTex_ST;
		
		struct v2f {
		    float4 pos : SV_POSITION;
		    float2 uv : TEXCOORD0;
		};

		v2f vert (appdata_base v)
		{
		    v2f o;
		    float4 vPos = mul (UNITY_MATRIX_MV, v.vertex);
		    float zOff = vPos.z/_Dist;
		    vPos += _QOffset*zOff*zOff;
		    o.pos = mul (UNITY_MATRIX_P, vPos);
		    o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);
		    return o;
		}

		half4 frag (v2f i) : COLOR
		{
		    return tex2D(_MainTex, i.uv) * float4(1,1,1,_Alpha);
		}
		ENDCG
	}
}

FallBack “Platogo/Unlit Texture Alpha”
}

in the Properties { }, add _Color ("Main Color", Color) = (0, 0, 0 ,1) and above struct v2f { add float4 _Color;

In your frag function, replace float4(1,1,1,_Alpha) with _Color.