Merge pull request #2761 from tacaswell/fix_line_color_handling

Fix line color handling

lib/matplotlib/lines.py

@@ -527,7 +527,7 @@ def draw(self, renderer):
         self._set_gc_clip(gc)
 
         ln_color_rgba = self._get_rgba_ln_color()
-        gc.set_foreground(ln_color_rgba)
+        gc.set_foreground(ln_color_rgba, isRGBA=True)
         gc.set_alpha(ln_color_rgba[3])
 
         gc.set_antialiased(self._antialiased)
@@ -569,7 +569,7 @@ def draw(self, renderer):
             edgecolor = self.get_markeredgecolor()
             if is_string_like(edgecolor) and edgecolor.lower() == 'none':
                 gc.set_linewidth(0)
-                gc.set_foreground(rgbaFace)
+                gc.set_foreground(rgbaFace, isRGBA=True)
             else:
                 gc.set_foreground(edgecolor)
                 gc.set_linewidth(self._markeredgewidth)
@@ -1031,12 +1031,7 @@ def _get_rgba_face(self, alt=False):
         return rgbaFace
 
     def _get_rgba_ln_color(self, alt=False):
-        ln_color = self._color
-        if is_string_like(ln_color) and ln_color.lower() == 'none':
-            rgba_ln = None
-        else:
-            rgba_ln = colorConverter.to_rgba(ln_color, self._alpha)
-        return rgba_ln
+        return colorConverter.to_rgba(self._color, self._alpha)
 
     # some aliases....
     def set_aa(self, val):

lib/matplotlib/tests/test_lines.py

@@ -14,7 +14,7 @@
 def test_invisible_Line_rendering():
     """
     Github issue #1256 identified a bug in Line.draw method
-    
+
     Despite visibility attribute set to False, the draw method was not
     returning early enough and some pre-rendering code was executed
     though not necessary.
@@ -67,6 +67,19 @@ def test_set_line_coll_dash():
     assert True
 
 
+@cleanup
+def test_line_colors():
+    fig = plt.figure()
+    ax = fig.add_subplot(1, 1, 1)
+    ax.plot(range(10), color='none')
+    ax.plot(range(10), color='r')
+    ax.plot(range(10), color='.3')
+    ax.plot(range(10), color=(1, 0, 0, 1))
+    ax.plot(range(10), color=(1, 0, 0))
+    fig.canvas.draw()
+    assert True
+
+
 @image_comparison(baseline_images=['line_collection_dashes'], remove_text=True)
 def test_set_line_coll_dash_image():
     fig = plt.figure()