diff --git a/tryton/gui/window/view_form/view/form_gtk/interface.py b/tryton/gui/window/view_form/view/form_gtk/interface.py
index cb4a2823e8..e6746abf42 100644
--- a/tryton/gui/window/view_form/view/form_gtk/interface.py
+++ b/tryton/gui/window/view_form/view/form_gtk/interface.py
@@ -93,13 +93,7 @@ class WidgetInterface(object):
         ]
         self.widget = None
         self.position = 0
-        self.bg_color_active = None
-        self.bg_color_insensitive = None
-        self.base_color_normal = None
-        self.base_color_insensitive = None
-        self.fg_color_normal = None
-        self.fg_color_insensitive = None
-        self.text_color_normal = None
+        self.colors = {}
         self.visible = True
 
     def destroy(self):
@@ -156,25 +150,21 @@ class WidgetInterface(object):
 
     def color_set(self, name):
         widget = self._color_widget()
-        colormap = widget.get_colormap()
-        style = widget.get_style()
 
-        if self.bg_color_active is None:
-            self.bg_color_active = style.bg[gtk.STATE_ACTIVE]
-        if self.bg_color_insensitive is None:
-            self.bg_color_insensitive = style.bg[gtk.STATE_INSENSITIVE]
-        if self.base_color_normal is None:
-            self.base_color_normal = style.base[gtk.STATE_NORMAL]
-        if self.base_color_insensitive is None:
-            self.base_color_insensitive = style.base[gtk.STATE_INSENSITIVE]
-        if self.fg_color_normal is None:
-            self.fg_color_normal = style.fg[gtk.STATE_NORMAL]
-        if self.fg_color_insensitive is None:
-            self.fg_color_insensitive = style.fg[gtk.STATE_INSENSITIVE]
-        if self.text_color_normal is None:
-            self.text_color_normal = style.text[gtk.STATE_NORMAL]
+        if not self.colors:
+            style = widget.get_style()
+            self.colors = {
+                'bg_color_active': style.bg[gtk.STATE_ACTIVE],
+                'bg_color_insensitive': style.bg[gtk.STATE_INSENSITIVE],
+                'base_color_normal': style.base[gtk.STATE_NORMAL],
+                'base_color_insensitive': style.base[gtk.STATE_INSENSITIVE],
+                'fg_color_normal': style.fg[gtk.STATE_NORMAL],
+                'fg_color_insensitive': style.fg[gtk.STATE_INSENSITIVE],
+                'text_color_normal': style.text[gtk.STATE_NORMAL],
+            }
 
         if COLORS.get(name):
+            colormap = widget.get_colormap()
             bg_color = colormap.alloc_color(COLORS.get(name, 'white'))
             fg_color = gtk.gdk.color_parse("black")
             widget.modify_bg(gtk.STATE_ACTIVE, bg_color)
@@ -183,17 +173,27 @@ class WidgetInterface(object):
             widget.modify_text(gtk.STATE_NORMAL, fg_color)
             widget.modify_text(gtk.STATE_INSENSITIVE, fg_color)
         elif name == 'readonly':
-            widget.modify_bg(gtk.STATE_ACTIVE, self.bg_color_insensitive)
-            widget.modify_base(gtk.STATE_NORMAL, self.base_color_insensitive)
-            widget.modify_fg(gtk.STATE_NORMAL, self.fg_color_insensitive)
-            widget.modify_text(gtk.STATE_NORMAL, self.text_color_normal)
-            widget.modify_text(gtk.STATE_INSENSITIVE, self.text_color_normal)
+            widget.modify_bg(gtk.STATE_ACTIVE,
+                    self.colors['bg_color_insensitive'])
+            widget.modify_base(gtk.STATE_NORMAL,
+                    self.colors['base_color_insensitive'])
+            widget.modify_fg(gtk.STATE_NORMAL,
+                    self.colors['fg_color_insensitive'])
+            widget.modify_text(gtk.STATE_NORMAL,
+                    self.colors['text_color_normal'])
+            widget.modify_text(gtk.STATE_INSENSITIVE,
+                    self.colors['text_color_normal'])
         else:
-            widget.modify_bg(gtk.STATE_ACTIVE, self.bg_color_active)
-            widget.modify_base(gtk.STATE_NORMAL, self.base_color_normal)
-            widget.modify_fg(gtk.STATE_NORMAL, self.fg_color_normal)
-            widget.modify_text(gtk.STATE_NORMAL, self.text_color_normal)
-            widget.modify_text(gtk.STATE_INSENSITIVE, self.text_color_normal)
+            widget.modify_bg(gtk.STATE_ACTIVE,
+                    self.colors['bg_color_active'])
+            widget.modify_base(gtk.STATE_NORMAL,
+                    self.colors['base_color_normal'])
+            widget.modify_fg(gtk.STATE_NORMAL,
+                    self.colors['fg_color_normal'])
+            widget.modify_text(gtk.STATE_NORMAL,
+                    self.colors['text_color_normal'])
+            widget.modify_text(gtk.STATE_INSENSITIVE,
+                    self.colors['text_color_normal'])
 
     def invisible_set(self, value):
         widget = self._invisible_widget()