Revert change from NoneType to 0

Author: Jason Symons

adafruit_is31fl3741/__init__.py

@@ -293,7 +293,7 @@ def pixel_addrs(x: int, y: int) -> Tuple[int, ...]:
         """Calculate a device-specific LED offset for an X,Y 2D pixel."""
         raise NotImplementedError("Supported in subclasses only")
 
-    def fill(self, color: int = 0) -> None:
+    def fill(self, color: Optional[int] = None) -> None:
         """Set all pixels to a given RGB color.
 
         :param color: Packed 24-bit color value (0xRRGGBB).
@@ -308,7 +308,7 @@ def fill(self, color: int = 0) -> None:
                 self[addrs[self.g_offset]] = green
                 self[addrs[self.b_offset]] = blue
 
-    def pixel(self, x: int, y: int, color: int = None) -> Union[int, None]:
+    def pixel(self, x: int, y: int, color: Optional[int] = None) -> Union[int, None]:
         """
         Set or retrieve RGB color of pixel at position (X,Y).