Unlit/transparent shader that can flash the textures white (pure black is all original texture, white is all white)

unlit-transparent-flash-fx.shader

Shader "Unlit/TransparentFlashFX" {
    Properties {
        _Color ("Color Tint", Color) = (1,1,1,1)
        _MainTex ("SelfIllum Color (RGB) Alpha (A)", 2D) = "white"
    }
    Category {
       Lighting On
       ZWrite Off
       Cull Back
       Blend SrcAlpha OneMinusSrcAlpha
       Tags {Queue=Transparent}
       SubShader {
            Material {
               Emission [_Color]
            }
            Pass {
               SetTexture [_MainTex] {
                      Combine Texture + Primary, Texture
                }
            }
        } 
    }
}

For what it's worth, you can use this in wherever. MIT license.