Merge pull request matplotlib#26249 from artemshekh/fix-axes3d.scatter-color-handling

    FIX: axes3d.scatter color parameter doesn't decrease in size for non-finite coordinate inputs.

Author: oscargus

lib/mpl_toolkits/mplot3d/axes3d.py

@@ -2310,7 +2310,11 @@ def scatter(self, xs, ys, zs=0, zdir='z', s=20, c=None, depthshade=True,
             *[np.ravel(np.ma.filled(t, np.nan)) for t in [xs, ys, zs]])
         s = np.ma.ravel(s)  # This doesn't have to match x, y in size.
 
-        xs, ys, zs, s, c = cbook.delete_masked_points(xs, ys, zs, s, c)
+        xs, ys, zs, s, c, color = cbook.delete_masked_points(
+            xs, ys, zs, s, c, kwargs.get('color', None)
+            )
+        if kwargs.get('color', None):
+            kwargs['color'] = color
 
         # For xs and ys, 2D scatter() will do the copying.
         if np.may_share_memory(zs_orig, zs):  # Avoid unnecessary copies.

lib/mpl_toolkits/mplot3d/tests/test_axes3d.py

@@ -2208,3 +2208,29 @@ def test_mutating_input_arrays_y_and_z(fig_test, fig_ref):
     y = [0.0, 0.0, 0.0]
     z = [0.0, 0.0, 0.0]
     ax2.plot(x, y, z, 'o-')
+
+
+def test_scatter_masked_color():
+    """
+    Test color parameter usage with non-finite coordinate arrays.
+
+    GH#26236
+    """
+
+    x = [np.nan, 1, 2,  1]
+    y = [0, np.inf, 2,  1]
+    z = [0, 1, -np.inf, 1]
+    colors = [
+        [0.0, 0.0, 0.0, 1],
+        [0.0, 0.0, 0.0, 1],
+        [0.0, 0.0, 0.0, 1],
+        [0.0, 0.0, 0.0, 1]
+    ]
+
+    fig = plt.figure()
+    ax = fig.add_subplot(projection='3d')
+    path3d = ax.scatter(x, y, z, color=colors)
+
+    # Assert sizes' equality
+    assert len(path3d.get_offsets()) ==\
+           len(super(type(path3d), path3d).get_facecolors())