Sprite color invert

@darius0021 if its for a sprite then I don't have the awnser but if it's for a mesh then the code would be like this

 Shader "Custom/Invert Colors" {
     Properties {
         // defines color property
         _Color("Tint Color", Color) = (1,1,1,1)
     }
 
     SubShader{
         // sets the queue to transparent
         Tags{ "Queue" = "Transparent" }
 
         Pass { ColorMask 0 } // turns off rendering to all color channels
         Blend OneMinusDstColor OneMinusSrcAlpha //invert blending, so long as FG color is 1,1,1,1
         BlendOp Add // adds source and destination together with specified blend modes
 
         Pass
         {
             CGPROGRAM
             #pragma vertex vert
             #pragma fragment frag
             uniform float4 _Color;
 
             struct vertexInput
             {
                 float4 vertex: POSITION;
                 float4 color : COLOR;
             };
 
             struct fragmentInput
             {
                 float4 pos : SV_POSITION;
                 float4 color : COLOR0;
             };
 
             fragmentInput vert(vertexInput i)
             {
                 fragmentInput o;
                 o.pos = UnityObjectToClipPos(i.vertex);
                 o.color = _Color;
                 return o;
             }
 
             half4 frag(fragmentInput i) : COLOR
             {
                 return i.color;
             }
 
             ENDCG
         }
     }
 }

I hope this helps