diff --git a/src/fr/impl/Parts/Exterior.java b/src/fr/impl/Parts/Exterior.java
index 74dc158..389b866 100644
--- a/src/fr/impl/Parts/Exterior.java
+++ b/src/fr/impl/Parts/Exterior.java
@@ -21,26 +21,22 @@ public class Exterior extends PartImpl {
           colorSet.add("gray");
       }
 
+      private String color;
 
      public Exterior(String name, CategoryImpl category, int price){
           super(new PartTypeImpl(name,Engine.class, category),price);
 
           Set<String> l = new HashSet<String>();
           l.add("red");
-          this.addProperty("color", () -> getColor(), p -> setColor(p), colorSet);
+          this.addProperty("color", () -> getColor(), c -> setColor(c), colorSet);
      }
 
 
      public String getColor(){
-          String result = "white";
-          Optional<String> color = this.getProperty("color");
-          if(color.isPresent()){
-               result = color.get();
-          }
-          return result;
+          return this.color;
      }
 
      public void setColor(String newColor){
-          this.setProperty("color",newColor);
+          this.color = newColor;
      }
 }
diff --git a/src/fr/test/test.java b/src/fr/test/test.java
index f2047d1..adbebde 100644
--- a/src/fr/test/test.java
+++ b/src/fr/test/test.java
@@ -221,8 +221,8 @@ public class test {
 
     @Test
     public void test_PropertyInteriorColor(){
-        XS.setColor("red");
-        assertTrue(XS.getColor()=="red");
+        XS.setProperty("color","red");
+        assertTrue(XS.getProperty("color").get()=="red");
     }