fix legends with labelcolor set to linecolor: change ordering from c, fc to mfc, fc, mec, ec, c; check if color is empty, none or transparent and loop on if so

lukashergt · lukashergt · commit 335e76e350a0 · 2025-07-18T04:01:11.000+02:00
diff --git a/lib/matplotlib/legend.py b/lib/matplotlib/legend.py
@@ -576,7 +576,11 @@ def __init__(
         # set the text color
 
         color_getters = {  # getter function depends on line or patch
-            'linecolor':       ['get_color',           'get_facecolor'],
+            'linecolor':       ['get_markerfacecolor',
+                                'get_facecolor',
+                                'get_markeredgecolor',
+                                'get_edgecolor',
+                                'get_color'],
             'markerfacecolor': ['get_markerfacecolor', 'get_facecolor'],
             'mfc':             ['get_markerfacecolor', 'get_facecolor'],
             'markeredgecolor': ['get_markeredgecolor', 'get_edgecolor'],
@@ -596,18 +600,27 @@ def __init__(
                     try:
                         color = getattr(handle, getter_name)()
                         if isinstance(color, np.ndarray):
-                            if (
-                                    color.shape[0] == 1
-                                    or np.isclose(color, color[0]).all()
+                            if color.size == 0:
+                                continue
+                            elif (
+                                color.shape[0] == 1
+                                or np.isclose(color, color[0]).all()
                             ):
                                 text.set_color(color[0])
                             else:
                                 pass
+                        elif isinstance(color, str) and str(color).lower() == 'none':
+                            continue
+                        elif (len(mpl.colors.to_rgba(color)) == 4
+                              and mpl.colors.to_rgba(color)[3] == 0):
+                                continue
                         else:
                             text.set_color(color)
                         break
                     except AttributeError:
-                        pass
+                        continue
+                else:
+                    text.set_color('none')
         elif cbook._str_equal(labelcolor, 'none'):
             for text in self.texts:
                 text.set_color(labelcolor)
