matplotlib · nrnavaneet · Jul 12, 2025 · Jul 12, 2025 · Jul 12, 2025 · Jul 12, 2025
diff --git a/lib/matplotlib/__init__.pyi b/lib/matplotlib/__init__.pyi
@@ -39,8 +39,10 @@ import contextlib
 from packaging.version import Version
 
 from matplotlib._api import MatplotlibDeprecationWarning
+from matplotlib.typing import LogLevel
 from typing import Any, Literal, NamedTuple, overload
 
+
 class _VersionInfo(NamedTuple):
     major: int
     minor: int
@@ -52,7 +54,7 @@ __bibtex__: str
 __version__: str
 __version_info__: _VersionInfo
 
-def set_loglevel(level: str) -> None: ...
+def set_loglevel(level: LogLevel) -> None: ...
 
 class _ExecInfo(NamedTuple):
     executable: str

diff --git a/lib/matplotlib/legend.py b/lib/matplotlib/legend.py
@@ -576,7 +576,7 @@ def __init__(
         # set the text color
 
         color_getters = {  # getter function depends on line or patch
-            'linecolor':       ['get_color',           'get_facecolor'],
+            'linecolor':       ['get_facecolor', 'get_edgecolor', 'get_color'],
             'markerfacecolor': ['get_markerfacecolor', 'get_facecolor'],
             'mfc':             ['get_markerfacecolor', 'get_facecolor'],
             'markeredgecolor': ['get_markeredgecolor', 'get_edgecolor'],
@@ -592,32 +592,43 @@ def __init__(
                         continue
                 except AttributeError:
                     pass
+
                 for getter_name in getter_names:
                     try:
                         color = getattr(handle, getter_name)()
+
                         if isinstance(color, np.ndarray):
-                            if (
-                                    color.shape[0] == 1
-                                    or np.isclose(color, color[0]).all()
-                            ):
-                                text.set_color(color[0])
+                            if color.size == 0:
+                                continue
+                            if color.shape[0] == 1 or np.isclose(color, color[0]).all():
+                                rgba = color[0]
                             else:
-                                pass
+                                continue  # Gradient or ambiguous color
                         else:
-                            text.set_color(color)
+                            rgba = color
+
+                        # Skip if fully transparent (invisible legend text)
+                        if (
+                            hasattr(rgba, '__getitem__')
+                            and len(rgba) == 4 and rgba[3] == 0
+                            ):
+                            continue
+
+                        text.set_color(rgba)
                         break
                     except AttributeError:
                         pass
-        elif cbook._str_equal(labelcolor, 'none'):
-            for text in self.texts:
-                text.set_color(labelcolor)
-        elif np.iterable(labelcolor):
-            for text, color in zip(self.texts,
-                                   itertools.cycle(
-                                       colors.to_rgba_array(labelcolor))):
-                text.set_color(color)
         else:
-            raise ValueError(f"Invalid labelcolor: {labelcolor!r}")
+            if cbook._str_equal(labelcolor, 'none'):
+                for text in self.texts:
+                    text.set_color(labelcolor)
+            elif np.iterable(labelcolor):
+                for text, color in zip(self.texts,
+                                    itertools.cycle(colors.to_rgba_array(labelcolor))):
+                    text.set_color(color)
+            else:
+                for text in self.texts:
+                    text.set_color(labelcolor)
 
     def _set_artist_props(self, a):
         """

diff --git a/lib/matplotlib/pyplot.py b/lib/matplotlib/pyplot.py
@@ -144,6 +144,7 @@
         MouseEventType,
         PickEventType,
         ResizeEventType,
+        LogLevel
     )
     from matplotlib.widgets import SubplotTool
 
@@ -351,7 +352,7 @@ def uninstall_repl_displayhook() -> None:
 
 # Ensure this appears in the pyplot docs.
 @_copy_docstring_and_deprecators(matplotlib.set_loglevel)
-def set_loglevel(level: str) -> None:
+def set_loglevel(level: LogLevel) -> None:
     return matplotlib.set_loglevel(level)
 
 

diff --git a/lib/matplotlib/tests/test_legend.py b/lib/matplotlib/tests/test_legend.py
@@ -22,6 +22,9 @@
 import matplotlib.legend as mlegend
 from matplotlib import rc_context
 from matplotlib.font_manager import FontProperties
+import matplotlib.colors as mcolors
+
+
 
 
 def test_legend_ordereddict():
@@ -1472,3 +1475,31 @@ def test_boxplot_legend_labels():
     bp4 = axs[3].boxplot(data, label='box A')
     assert bp4['medians'][0].get_label() == 'box A'
     assert all(x.get_label().startswith("_") for x in bp4['medians'][1:])
+
+
+def test_legend_labelcolor_linecolor_default_artists():
+    fig, axes = plt.subplots(2, 2)
+    x = np.random.randn(1000)
+    y = np.random.randn(1000)
+
+    # Top Left: Filled Histogram (default color C0)
+    axes[0, 0].hist(x, histtype='bar', label="spam")
+    leg00 = axes[0, 0].legend(labelcolor='linecolor')
+    assert np.allclose(leg00.get_texts()[0].get_color()[:3], mcolors.to_rgb('C0'))
+
+    # Top Right: Step Histogram (default color C0)
+    axes[0, 1].hist(x, histtype='step', label="spam")
+    leg01 = axes[0, 1].legend(labelcolor='linecolor')
+    assert np.allclose(leg01.get_texts()[0].get_color()[:3], mcolors.to_rgb('C0'))
+
+    # Bottom Left: Scatter (filled, default color C0)
+    axes[1, 0].scatter(x, y, label="spam")
+    leg10 = axes[1, 0].legend(labelcolor='linecolor')
+    assert np.allclose(leg10.get_texts()[0].get_color()[:3], mcolors.to_rgb('C0'))
+
+    # Bottom Right: Scatter (outline, default edge color C0)
+    axes[1, 1].scatter(x, y, label="spam")
+    leg11 = axes[1, 1].legend(labelcolor='linecolor')
+    assert np.allclose(leg11.get_texts()[0].get_color()[:3], mcolors.to_rgb('C0'))
+
+    plt.close(fig)
diff --git a/lib/matplotlib/typing.py b/lib/matplotlib/typing.py
@@ -77,6 +77,10 @@
 FillStyleType: TypeAlias = Literal["full", "left", "right", "bottom", "top", "none"]
 """Marker fill styles. See :doc:`/gallery/lines_bars_and_markers/marker_reference`."""
 
+LogLevel: TypeAlias = Literal["notset", "debug", "info", "warning", "error", "critical"]
+"""Valid string values for logging levels used in `set_loglevel`."""
+
+
 JoinStyleType: TypeAlias = JoinStyle | Literal["miter", "round", "bevel"]
 """Line join styles. See :doc:`/gallery/lines_bars_and_markers/joinstyle`."""