Fix typing for color565 function

Author: makermelissa

adafruit_rgb_display/rgb.py

@@ -47,14 +47,14 @@
 
 
 def color565(
-    r: Union[int, Tuple[int, int, int], List[int]],
-    g: int = 0,
-    b: int = 0,
+    r: Union[int, Tuple[int, int, int], List[int, int, int]],
+    g: Optional[int] = 0,
+    b: Optional[int] = 0,
 ) -> int:
     """Convert red, green and blue values (0-255) into a 16-bit 565 encoding.  As
     a convenience this is also available in the parent adafruit_rgb_display
     package namespace."""
-    if not isinstance(r, int):  # see if the first var is a tuple/list
+    if isinstance(r, (tuple, list)):  # see if the first var is a tuple/list
         red, g, b = r
     else:
         red = r