Mar 7, 2025
diff --git a/lib/matplotlib/collections.py b/lib/matplotlib/collections.py
        return mpl.rcParams['patch.facecolor']

    def _set_facecolor(self, c):
        if self.get_array() is not None:
            # Note: we cannot use self._face_is_mapped here because it is
            # lazily calculated in update_scalarmappable(), but the equivalent
            # logic there is that colormapping from an array takes precedence
            # over an explicit facecolor.
            _api.warn_external(
                "Setting the facecolor has no effect because there is colormapped "
                "array data, which takes precedence. Use `set_array(None)` before "
                "setting the facecolor to override this.")

        if c is None:
            c = self._get_default_facecolor()

diff --git a/lib/matplotlib/tests/test_collections.py b/lib/matplotlib/tests/test_collections.py
    assert ax.dataLim.bounds == bounds


 def test_collection_facecolor():
    pc = plt.figure().subplots().scatter([0, 1, 2], [0, 1, 2], c=[0, 0.5, 1])
    with pytest.warns(match="Setting the facecolor has no effect"):
        pc.set_facecolor(['r', 'g', 'b'])
    # the returned facecolor is the colormapped one:
    pc.get_facecolor() == plt.get_cmap()([0, 0.5, 1])


 @mpl.style.context('mpl20')
 @check_figures_equal(extensions=['png'])
 def test_collection_log_datalim(fig_test, fig_ref):
Original file line number	Diff line number	Diff line change
Expand Up		@@ -778,6 +778,16 @@ def _get_default_facecolor(self):
		return mpl.rcParams['patch.facecolor']

		def _set_facecolor(self, c):
		if self.get_array() is not None:
		# Note: we cannot use self._face_is_mapped here because it is
		# lazily calculated in update_scalarmappable(), but the equivalent
		# logic there is that colormapping from an array takes precedence
		# over an explicit facecolor.
		_api.warn_external(
		"Setting the facecolor has no effect because there is colormapped "
		"array data, which takes precedence. Use `set_array(None)` before "
		"setting the facecolor to override this.")

		if c is None:
		c = self._get_default_facecolor()

Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -333,6 +333,14 @@ def test_add_collection():
		assert ax.dataLim.bounds == bounds


		def test_collection_facecolor():
		pc = plt.figure().subplots().scatter([0, 1, 2], [0, 1, 2], c=[0, 0.5, 1])
		with pytest.warns(match="Setting the facecolor has no effect"):
		pc.set_facecolor(['r', 'g', 'b'])
		# the returned facecolor is the colormapped one:
		pc.get_facecolor() == plt.get_cmap()([0, 0.5, 1])


		@mpl.style.context('mpl20')
		@check_figures_equal(extensions=['png'])
		def test_collection_log_datalim(fig_test, fig_ref):
Expand Down