diff --git a/lib/matplotlib/backends/qt_editor/figureoptions.py b/lib/matplotlib/backends/qt_editor/figureoptions.py
index 5094a3045255..063af6820220 100644
--- a/lib/matplotlib/backends/qt_editor/figureoptions.py
+++ b/lib/matplotlib/backends/qt_editor/figureoptions.py
@@ -15,17 +15,17 @@
 import os.path as osp
 import re
 
+import matplotlib
+from matplotlib import cm, markers, colors as mcolors
 import matplotlib.backends.qt_editor.formlayout as formlayout
 from matplotlib.backends.qt_compat import QtGui
-from matplotlib import cm, markers
-from matplotlib.colors import colorConverter, rgb2hex
 
 
 def get_icon(name):
-    import matplotlib
     basedir = osp.join(matplotlib.rcParams['datapath'], 'images')
     return QtGui.QIcon(osp.join(basedir, name))
 
+
 LINESTYLES = {'-': 'Solid',
               '--': 'Dashed',
               '-.': 'DashDot',
@@ -114,23 +114,25 @@ def prepare_data(d, init):
     curvelabels = sorted(linedict, key=cmp_key)
     for label in curvelabels:
         line = linedict[label]
-        color = rgb2hex(colorConverter.to_rgb(line.get_color()))
-        ec = rgb2hex(colorConverter.to_rgb(line.get_markeredgecolor()))
-        fc = rgb2hex(colorConverter.to_rgb(line.get_markerfacecolor()))
+        color = mcolors.to_hex(
+            mcolors.to_rgba(line.get_color(), line.get_alpha()),
+            keep_alpha=True)
+        ec = mcolors.to_hex(line.get_markeredgecolor(), keep_alpha=True)
+        fc = mcolors.to_hex(line.get_markerfacecolor(), keep_alpha=True)
         curvedata = [
             ('Label', label),
             sep,
             (None, '<b>Line</b>'),
-            ('Line Style', prepare_data(LINESTYLES, line.get_linestyle())),
-            ('Draw Style', prepare_data(DRAWSTYLES, line.get_drawstyle())),
+            ('Line style', prepare_data(LINESTYLES, line.get_linestyle())),
+            ('Draw style', prepare_data(DRAWSTYLES, line.get_drawstyle())),
             ('Width', line.get_linewidth()),
-            ('Color', color),
+            ('Color (RGBA)', color),
             sep,
             (None, '<b>Marker</b>'),
             ('Style', prepare_data(MARKERS, line.get_marker())),
             ('Size', line.get_markersize()),
-            ('Facecolor', fc),
-            ('Edgecolor', ec)]
+            ('Face color (RGBA)', fc),
+            ('Edge color (RGBA)', ec)]
         curves.append([curvedata, label, ""])
     # Is there a curve displayed?
     has_curve = bool(curves)
@@ -206,7 +208,9 @@ def apply_callback(data):
             line.set_linestyle(linestyle)
             line.set_drawstyle(drawstyle)
             line.set_linewidth(linewidth)
-            line.set_color(color)
+            rgba = mcolors.to_rgba(color)
+            line.set_color(rgba[:3])
+            line.set_alpha(rgba[-1])
             if marker is not 'none':
                 line.set_marker(marker)
                 line.set_markersize(markersize)
diff --git a/lib/matplotlib/backends/qt_editor/formlayout.py b/lib/matplotlib/backends/qt_editor/formlayout.py
index 9acf9a207f32..00a1a03a36ee 100644
--- a/lib/matplotlib/backends/qt_editor/formlayout.py
+++ b/lib/matplotlib/backends/qt_editor/formlayout.py
@@ -32,40 +32,33 @@
 FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 OTHER DEALINGS IN THE SOFTWARE.
 """
-from __future__ import (absolute_import, division, print_function,
-                        unicode_literals)
-
-import six
-from six.moves import xrange
 
 # History:
 # 1.0.10: added float validator (disable "Ok" and "Apply" button when not valid)
 # 1.0.7: added support for "Apply" button
 # 1.0.6: code cleaning
 
+from __future__ import (absolute_import, division, print_function,
+                        unicode_literals)
+
 __version__ = '1.0.10'
 __license__ = __doc__
 
 DEBUG = False
 
-import sys
-STDERR = sys.stderr
+import copy
+import datetime
+import warnings
+
+import six
 
-from matplotlib.colors import is_color_like
-from matplotlib.colors import rgb2hex
-from matplotlib.colors import colorConverter
+from matplotlib import colors as mcolors
 from matplotlib.backends.qt_compat import QtGui, QtWidgets, QtCore
 
-import datetime
 
 BLACKLIST = set(["title", "label"])
 
 
-def col2hex(color):
-    """Convert matplotlib color to hex before passing to Qt"""
-    return rgb2hex(colorConverter.to_rgb(color))
-
-
 class ColorButton(QtWidgets.QPushButton):
     """
     Color choosing push button
@@ -80,7 +73,9 @@ def __init__(self, parent=None):
         self._color = QtGui.QColor()
 
     def choose_color(self):
-        color = QtWidgets.QColorDialog.getColor(self._color, self.parentWidget(), '')
+        color = QtWidgets.QColorDialog.getColor(
+            self._color, self.parentWidget(), "",
+            QtWidgets.QColorDialog.ShowAlphaChannel)
         if color.isValid():
             self.set_color(color)
 
@@ -98,21 +93,17 @@ def set_color(self, color):
 
     color = QtCore.Property(QtGui.QColor, get_color, set_color)
 
-def col2hex(color):
-    """Convert matplotlib color to hex before passing to Qt"""
-    return rgb2hex(colorConverter.to_rgb(color))
 
 def to_qcolor(color):
     """Create a QColor from a matplotlib color"""
     qcolor = QtGui.QColor()
-    color = str(color)
     try:
-        color = col2hex(color)
+        rgba = mcolors.to_rgba(color)
     except ValueError:
-        #print('WARNING: ignoring invalid color %r' % color)
+        warnings.warn('Ignoring invalid color %r' % color)
         return qcolor  # return invalid QColor
-    qcolor.setNamedColor(color)  # set using hex color
-    return qcolor  # return valid QColor
+    qcolor.setRgbF(*rgba)
+    return qcolor
 
 
 class ColorLayout(QtWidgets.QHBoxLayout):
@@ -120,7 +111,8 @@ class ColorLayout(QtWidgets.QHBoxLayout):
     def __init__(self, color, parent=None):
         QtWidgets.QHBoxLayout.__init__(self)
         assert isinstance(color, QtGui.QColor)
-        self.lineedit = QtWidgets.QLineEdit(color.name(), parent)
+        self.lineedit = QtWidgets.QLineEdit(
+            mcolors.to_hex(color.getRgbF(), keep_alpha=True), parent)
         self.lineedit.editingFinished.connect(self.update_color)
         self.addWidget(self.lineedit)
         self.colorbtn = ColorButton(parent)
@@ -134,7 +126,7 @@ def update_color(self):
         self.colorbtn.color = qcolor  # defaults to black if not qcolor.isValid()
 
     def update_text(self, color):
-        self.lineedit.setText(color.name())
+        self.lineedit.setText(mcolors.to_hex(color.getRgbF(), keep_alpha=True))
 
     def text(self):
         return self.lineedit.text()
@@ -143,7 +135,7 @@ def text(self):
 def font_is_installed(font):
     """Check if font is installed"""
     return [fam for fam in QtGui.QFontDatabase().families()
-              if six.text_type(fam) == font]
+            if six.text_type(fam) == font]
 
 
 def tuple_to_qfont(tup):
@@ -151,11 +143,11 @@ def tuple_to_qfont(tup):
     Create a QFont from tuple:
         (family [string], size [int], italic [bool], bold [bool])
     """
-    if not isinstance(tup, tuple) or len(tup) != 4 \
-       or not font_is_installed(tup[0]) \
-       or not isinstance(tup[1], int) \
-       or not isinstance(tup[2], bool) \
-       or not isinstance(tup[3], bool):
+    if not (isinstance(tup, tuple) and len(tup) == 4
+            and font_is_installed(tup[0])
+            and isinstance(tup[1], int)
+            and isinstance(tup[2], bool)
+            and isinstance(tup[3], bool)):
         return None
     font = QtGui.QFont()
     family, size, italic, bold = tup
@@ -186,7 +178,7 @@ def __init__(self, value, parent=None):
         # Font size
         self.size = QtWidgets.QComboBox(parent)
         self.size.setEditable(True)
-        sizelist = list(xrange(6, 12)) + list(xrange(12, 30, 2)) + [36, 48, 72]
+        sizelist = list(range(6, 12)) + list(range(12, 30, 2)) + [36, 48, 72]
         size = font.pointSize()
         if size not in sizelist:
             sizelist.append(size)
@@ -224,8 +216,7 @@ class FormWidget(QtWidgets.QWidget):
     update_buttons = QtCore.Signal()
     def __init__(self, data, comment="", parent=None):
         QtWidgets.QWidget.__init__(self, parent)
-        from copy import deepcopy
-        self.data = deepcopy(data)
+        self.data = copy.deepcopy(data)
         self.widgets = []
         self.formlayout = QtWidgets.QFormLayout(self)
         if comment:
@@ -261,7 +252,8 @@ def setup(self):
                 continue
             elif tuple_to_qfont(value) is not None:
                 field = FontLayout(value, self)
-            elif label.lower() not in BLACKLIST and is_color_like(value):
+            elif (label.lower() not in BLACKLIST
+                  and mcolors.is_color_like(value)):
                 field = ColorLayout(to_qcolor(value), self)
             elif isinstance(value, six.string_types):
                 field = QtWidgets.QLineEdit(value, self)
@@ -281,8 +273,9 @@ def setup(self):
                 elif selindex in keys:
                     selindex = keys.index(selindex)
                 elif not isinstance(selindex, int):
-                    print("Warning: '%s' index is invalid (label: "
-                                    "%s, value: %s)" % (selindex, label, value), file=STDERR)
+                    warnings.warn(
+                        "index '%s' is invalid (label: %s, value: %s)" %
+                        (selindex, label, value))
                     selindex = 0
                 field.setCurrentIndex(selindex)
             elif isinstance(value, bool):
@@ -323,7 +316,8 @@ def get(self):
                 continue
             elif tuple_to_qfont(value) is not None:
                 value = field.get_font()
-            elif isinstance(value, six.string_types) or is_color_like(value):
+            elif (isinstance(value, six.string_types)
+                  or mcolors.is_color_like(value)):
                 value = six.text_type(field.text())
             elif isinstance(value, (list, tuple)):
                 index = int(field.currentIndex())
@@ -428,8 +422,8 @@ def __init__(self, data, title="", comment="",
         self.formwidget.setup()
 
         # Button box
-        self.bbox = bbox = QtWidgets.QDialogButtonBox(QtWidgets.QDialogButtonBox.Ok
-                                                 | QtWidgets.QDialogButtonBox.Cancel)
+        self.bbox = bbox = QtWidgets.QDialogButtonBox(
+            QtWidgets.QDialogButtonBox.Ok | QtWidgets.QDialogButtonBox.Cancel)
         self.formwidget.update_buttons.connect(self.update_buttons)
         if self.apply_callback is not None:
             apply_btn = bbox.addButton(QtWidgets.QDialogButtonBox.Apply)
@@ -454,7 +448,8 @@ def update_buttons(self):
         for field in self.float_fields:
             if not is_edit_valid(field):
                 valid = False
-        for btn_type in (QtWidgets.QDialogButtonBox.Ok, QtWidgets.QDialogButtonBox.Apply):
+        for btn_type in (QtWidgets.QDialogButtonBox.Ok,
+                         QtWidgets.QDialogButtonBox.Apply):
             btn = self.bbox.button(btn_type)
             if btn is not None:
                 btn.setEnabled(valid)