diff --git a/lib/matplotlib/backends/qt_editor/figureoptions.py b/lib/matplotlib/backends/qt_editor/figureoptions.py
index 669f9de6ce5..879b1cf6318 100644
--- a/lib/matplotlib/backends/qt_editor/figureoptions.py
+++ b/lib/matplotlib/backends/qt_editor/figureoptions.py
@@ -209,8 +209,8 @@ def apply_callback(data):
             line.set_drawstyle(drawstyle)
             line.set_linewidth(linewidth)
             rgba = mcolors.to_rgba(color)
-            line.set_color(rgba[:3])
-            line.set_alpha(rgba[-1])
+            line.set_alpha(None)
+            line.set_color(rgba)
             if marker is not 'none':
                 line.set_marker(marker)
                 line.set_markersize(markersize)