Colorea Shader Sin Perder Blanco

KeepSat.shader

Shader "Sprites/KeepSat"
{
    Properties
    {
        [PerRendererData] _MainTex ("Texture", 2D) = "white" {}
        _Color ("Tint", Color) = (1,1,1,1)
        _Exponente ("Exponente", Float) = 2.4
		[MaterialToggle] PixelSnap("Pixel snap", Float) = 0
		[MaterialToggle] Premultiply("Premultiply Alfa y Color", Int) = 1
        [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"
        }
        LOD 100
        Blend One OneMinusSrcAlpha
        Cull Off
        Lighting Off
        ZWrite Off
        //Blend SrcAlpha OneMinusSrcAlpha

        Pass
        {
            CGPROGRAM
            #pragma vertex SpriteVert
            #pragma fragment frag
            #pragma target 2.0
            #pragma multi_compile_instancing
			#pragma multi_compile _ PIXELSNAP_ON
			#pragma multi_compile _ PREMULTIPLY_ON
            #pragma multi_compile _ ETC1_EXTERNAL_ALPHA
            // make fog work
            #pragma multi_compile_fog

            //#include "UnityCG.cginc"
            #include "UnitySprites.cginc"

            /*struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
                float4 color : COLOR;
            };*/

            /*struct v2f
            {
                float2 uv : TEXCOORD0;
                float4 vertex : SV_POSITION;
                float4 color : COLOR;
            };*/

            /*v2f vert (appdata v)
            {
                v2f o;
                o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
                o.color = v.color;
                return o;
            }*/

            fixed _Exponente;

            fixed4 frag (v2f IN) : SV_Target
            {
                // sample the texture
                //fixed4 colTextura = tex2D(_MainTex, IN.texcoord);
                fixed4 colTextura = SampleSpriteTexture(IN.texcoord);
                fixed lum = Luminance(colTextura.rgb);
                colTextura.rgb *= lerp(IN.color.rgb,1.0, pow(lum,_Exponente) );
                colTextura.a *= IN.color.a;
                colTextura.rgb *= colTextura.a;
                return colTextura;
            }
            ENDCG
        }
    }
}