Head material was added

Models/Materials/IHeadMaterial.cs

@@ -0,0 +1,16 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Media;
+
+namespace StructureHelper.Models.Materials
+{
+    public interface IHeadMaterial
+    {
+        string Name { get; set; }
+        Color Color { get; set; }
+        MaterialDefinitionBase Material { get; set; }
+    }
+}