UnityEditor.ProjectWindowUtil.CreateNewGUISkin C# (CSharp) Method

        public static void CreateNewGUISkin()
        {
            GUISkin dest = ScriptableObject.CreateInstance<GUISkin>();
            GUISkin builtinResource = Resources.GetBuiltinResource(typeof(GUISkin), "GameSkin/GameSkin.guiskin") as GUISkin;
            if (builtinResource != null)
            {
                EditorUtility.CopySerialized(builtinResource, dest);
            }
            else
            {
                Debug.LogError("Internal error: unable to load builtin GUIskin");
            }
            CreateAsset(dest, "New GUISkin.guiskin");
        }