SpriteColourReplacement Shader

// Unity built-in shader source. Copyright (c) 2016 Unity Technologies. MIT license (see license.txt)

Shader "Custom/SpriteColourReplacement"
{
    Properties
    {
        [PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}
        _Color ("Tint", Color) = (1,1,1,1)

        [PerRendererData]
        _R ("R", Color) = (1,0,0,1)
        [PerRendererData]
        _G ("G", Color) = (0,1,0,1)
        [PerRendererData]
        _B ("B", Color) = (0,0,1,1)
        [PerRendererData]
        _C ("C", Color) = (0,1,1,1)
        [PerRendererData]
        _M ("M", Color) = (1,0,1,1)
        [PerRendererData]
        _Y ("Y", Color) = (1,1,0,1)

        [MaterialToggle] PixelSnap ("Pixel snap", Float) = 0
        [HideInInspector] _RendererColor ("RendererColor", Color) = (1,1,1,1)
        [HideInInspector] _Flip ("Flip", Vector) = (1,1,1,1)
        [PerRendererData] _AlphaTex ("External Alpha", 2D) = "white" {}
        [PerRendererData] _EnableExternalAlpha ("Enable External Alpha", Float) = 0
    }
     SubShader
    {
        Tags
        {
            "Queue"="Transparent"
            "IgnoreProjector"="True"
            "RenderType"="Transparent"
            "PreviewType"="Plane"
            "CanUseSpriteAtlas"="True"
        }

        Cull Off
        Lighting Off
        ZWrite Off
        Blend One OneMinusSrcAlpha

        Pass
        {
        CGPROGRAM
            #pragma vertex SpriteVert
            #pragma fragment frag
            #pragma target 2.0
            #pragma multi_compile_instancing
            #pragma multi_compile_local _ PIXELSNAP_ON
            #pragma multi_compile _ ETC1_EXTERNAL_ALPHA
            #include "UnitySprites.cginc"
            fixed4 _R;
            fixed4 _G;
            fixed4 _B;
            fixed4 _C;
            fixed4 _M;
            fixed4 _Y;

        fixed4 frag (v2f IN) : SV_Target
        {
            fixed4 c = SampleSpriteTexture (IN.texcoord);
            fixed4 cc = c * IN.color;
            if((c.r == 1 || c.r == 0) && (c.g == 1 || c.g == 0) && (c.b == 1 || c.b == 0)) {
                if(c.r == 1 && c.g == 1 && c.b == 0) {
                    c = _Y;
                } else if(c.r == 1 && c.g == 0 && c.b == 1) {
                    c = _M;
                } else if(c.r == 0 && c.g == 1 && c.b == 1) {
                    c = _C;
                } else if(c.r == 1 && c.g == 0 && c.b == 0) {
                    c = _R;
                } else if(c.r == 0 && c.g == 1 && c.b == 0) {
                    c = _G;
                } else if(c.r == 0 && c.g == 0 && c.b == 1) {
                    c = _B;
                }
            }
            c *= IN.color;
            c *= cc.a;
            return c;
        }
        ENDCG
        }
    }
}