Blank is Black rather

src/main.rs

@@ -50,14 +50,14 @@ impl Position for Point {
 
 impl IsBlank for Point {
     fn is_blank(&self) -> bool {
-        self.color == 0xffffff
+        self.color == 0
     }
 }
 
 impl Blanked for Point {
     fn blanked(&self) -> Self {
         Self {
-            color: 0xffffff,
+            color: 0,
             ..*self
         }
     }