UnityUrpVertexColoredShader

VertexColor.shader

// this shader using vertex color as input and show on meshes' surface.
// have searched a long time but there is no one upload a vertex-colored shader for urp so I made this.
// have a good day.
Shader "Example/VertexColor" {
    Properties
    {

    }
	SubShader {
        Tags { "RenderType" = "Opaque" "RenderPipeline" = "UniversalPipeline" }
		Pass
        {
			HLSLPROGRAM
			#pragma vertex vert
			#pragma fragment frag

            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"


			struct Attributes
			{
                float4 positionOS   : POSITION;
				float4 vertColor: COLOR;
			};

			struct Varyings {
                float4 positionHCS  : SV_POSITION;
				float4 color: COLOR;
			};

			Varyings vert(Attributes IN){
				Varyings OUT;
                OUT.positionHCS = TransformObjectToHClip(IN.positionOS.xyz);

				OUT.color = IN.vertColor;
				return OUT;
			}

			half4 frag(Varyings IN) : SV_Target
			{
				return IN.color.rgba;
				// return float4(0,0,1,0);
			}
			ENDHLSL
		}
	}
}

thanks! it still works in unity 6000.2.7