diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/GltfData.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/GltfData.cs
index 9ae339707..2a6227ad4 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/GltfData.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/GltfData.cs
@@ -330,9 +330,26 @@ namespace UniGLTF
             }
         }
 
+        // not black(0, 0, 0, 1)
+        static readonly UnityEngine.Color ZERO = new UnityEngine.Color(0, 0, 0, 0);
+
         public bool HasVertexColor(glTFAttributes attributes)
         {
-            return attributes.COLOR_0 != -1;
+            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)