update return types

Author: Michael Vincent Mannino

pandas/plotting/_matplotlib/core.py

@@ -1409,7 +1409,7 @@ def _get_c_values(self, color, color_by_categorical: bool, c_is_column: bool):
             c_values = c
         return c_values
 
-    def _are_valid_colors(self, c_values: Series):
+    def _are_valid_colors(self, c_values: Series) -> bool:
         # check if c_values contains strings and if these strings are valid mpl colors.
         # no need to check numerics as these (and mpl colors) will be validated for us
         # in .Axes.scatter._parse_scatter_color_args(...)
@@ -1423,7 +1423,7 @@ def _are_valid_colors(self, c_values: Series):
         except (TypeError, ValueError) as _:
             return False
 
-    def _get_color_mapping(self, c_values: Series) -> dict[str, str]:
+    def _get_color_mapping(self, c_values: Series) -> dict[str, np.ndarray]:
         unique = np.unique(c_values)
         n_colors = len(unique)