diff --git a/Assets/UniGLTF/Runtime/UniGLTF/Format/glTF.cs b/Assets/UniGLTF/Runtime/UniGLTF/Format/glTF.cs
index 6cc4a0912..e4557cea1 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/Format/glTF.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/Format/glTF.cs
@@ -81,36 +81,9 @@ namespace UniGLTF
             }
         }
 
-        public bool MaterialHasVertexColor(glTFMaterial material)
-        {
-            if (material == null)
-            {
-                return false;
-            }
-
-            var materialIndex = materials.IndexOf(material);
-            if (materialIndex == -1)
-            {
-                return false;
-            }
-
-            return MaterialHasVertexColor(materialIndex);
-        }
-
         [JsonSchema(MinItems = 1, ExplicitIgnorableItemLength = 0)]
         public List<glTFMesh> meshes = new List<glTFMesh>();
 
-        public bool MaterialHasVertexColor(int materialIndex)
-        {
-            if (materialIndex < 0 || materialIndex >= materials.Count)
-            {
-                return false;
-            }
-
-            var hasVertexColor = meshes.SelectMany(x => x.primitives).Any(x => x.material == materialIndex && x.HasVertexColor);
-            return hasVertexColor;
-        }
-
         [JsonSchema(MinItems = 1, ExplicitIgnorableItemLength = 0)]
         public List<glTFNode> nodes = new List<glTFNode>();
 
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/Format/glTFMesh.cs b/Assets/UniGLTF/Runtime/UniGLTF/Format/glTFMesh.cs
index 480f00519..9d945e064 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/Format/glTFMesh.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/Format/glTFMesh.cs
@@ -84,14 +84,6 @@ namespace UniGLTF
         [JsonSchema(Required = true, SkipSchemaComparison = true)]
         public glTFAttributes attributes;
 
-        public bool HasVertexColor
-        {
-            get
-            {
-                return attributes.COLOR_0 != -1;
-            }
-        }
-
         [JsonSchema(Minimum = 0)]
         public int material;
 
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/GltfData.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/GltfData.cs
index 614dc3ad2..19d720102 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/GltfData.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/GltfData.cs
@@ -329,5 +329,49 @@ namespace UniGLTF
                 return (GetBytesFromUri(image.uri), image.mimeType);
             }
         }
+
+        // not black(0, 0, 0, 1)
+        static readonly UnityEngine.Color ZERO = new UnityEngine.Color(0, 0, 0, 0);
+
+        public bool HasVertexColor(glTFAttributes attributes)
+        {
+            if (attributes.COLOR_0 == -1)
+            {
+                return false;
+            }
+
+            var colors = GetArrayFromAccessor<UnityEngine.Color>(attributes.COLOR_0);
+            foreach (var color in colors)
+            {
+                if (color != ZERO)
+                {
+                    return true;
+                }
+            }
+            // すべて (0, 0, 0, 0) だった。使っていないと見做す。
+            return false;
+        }
+
+        public bool MaterialHasVertexColor(int materialIndex)
+        {
+            if (materialIndex < 0 || materialIndex >= GLTF.materials.Count)
+            {
+                // index out of range. material not exists
+                return false;
+            }
+
+            foreach (var mesh in GLTF.meshes)
+            {
+                foreach (var prim in mesh.primitives)
+                {
+                    if (prim.material == materialIndex && HasVertexColor(prim.attributes))
+                    {
+                        return true;
+                    }
+                }
+            }
+
+            return false;
+        }
     }
 }
diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/GltfUnlitMaterialImporter.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/GltfUnlitMaterialImporter.cs
index bd422a7a0..7bbde1681 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/GltfUnlitMaterialImporter.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/MaterialIO/GltfUnlitMaterialImporter.cs
@@ -91,7 +91,7 @@ namespace UniGLTF
                         }
 
                         // VColor
-                        var hasVertexColor = data.GLTF.MaterialHasVertexColor(i);
+                        var hasVertexColor = data.MaterialHasVertexColor(i);
                         if (hasVertexColor)
                         {
                             UniUnlitUtil.SetVColBlendMode(material, UniUnlitVertexColorBlendOp.Multiply);