Raise warning if both c and facecolors are used in scatter plot. In the future we may implement c as edgecolors in that case or cause plot to fail.

NGWi · NGWi · commit 5a26bb9511bc · 2024-11-12T17:49:06.000-05:00
diff --git a/lib/matplotlib/axes/_axes.py b/lib/matplotlib/axes/_axes.py
@@ -4613,10 +4613,20 @@ def _parse_scatter_color_args(c, edgecolors, kwargs, xsize,
                 edgecolors = kwcolor
             if facecolors is None:
                 facecolors = kwcolor
-
+         
+ 
         if edgecolors is None and not mpl.rcParams['_internal.classic_mode']:
             edgecolors = mpl.rcParams['scatter.edgecolors']
 
+        # Raise a warning if both `c` and `facecolor` are set (issue #24404).
+        if c is not None and facecolors is not None:
+            _api.warn_external(
+                "You passed both c and facecolor/facecolors for the markers. "
+                "Matplotlib is ignoring the facecolor "
+                "in favor of what you specified in c. "
+                "This behavior may change in the future."
+            )
+
         c_was_none = c is None
         if c is None:
             c = (facecolors if facecolors is not None
