diff --git a/src/chat_control.py b/src/chat_control.py
index a186aebe3..65f49cca6 100644
--- a/src/chat_control.py
+++ b/src/chat_control.py
@@ -648,16 +648,20 @@ class ChatControlBase(MessageControl, ChatCommandProcessor, CommandTools):
         self.disconnect_style_event(banner_name_label)
         self.disconnect_style_event(self.banner_status_label)
         if bgcolor:
-            banner_eventbox.modify_bg(Gtk.StateType.NORMAL,
-                    Gdk.color_parse(bgcolor))
+            color = Gdk.RGBA()
+            Gdk.RGBA.parse(color, bgcolor)
+            banner_eventbox.override_background_color(Gtk.StateType.NORMAL,
+                color)
             default_bg = False
         else:
             default_bg = True
         if textcolor:
-            banner_name_label.modify_fg(Gtk.StateType.NORMAL,
-                    Gdk.color_parse(textcolor))
-            self.banner_status_label.modify_fg(Gtk.StateType.NORMAL,
-                    Gdk.color_parse(textcolor))
+            color = Gdk.RGBA()
+            Gdk.RGBA.parse(color, textcolor)
+            banner_name_label.override_background_color(Gtk.StateType.NORMAL,
+                color)
+            self.banner_status_label.override_background_color(
+                Gtk.StateType.NORMAL, color)
             default_fg = False
         else:
             default_fg = True
@@ -1183,8 +1187,8 @@ class ChatControlBase(MessageControl, ChatCommandProcessor, CommandTools):
 
     def update_font(self):
         font = Pango.FontDescription(gajim.config.get('conversation_font'))
-        self.conv_textview.tv.modify_font(font)
-        self.msg_textview.modify_font(font)
+        self.conv_textview.tv.override_font(font)
+        self.msg_textview.override_font(font)
 
     def update_tags(self):
         self.conv_textview.update_tags()
@@ -2434,8 +2438,8 @@ class ChatControl(ChatControlBase):
                 self.conv_textview.correct_last_sent_message(message, xhtml,
                     self.get_our_nick(), old_txt)
                 self.correcting = False
-                self.msg_textview.modify_base(Gtk.StateType.NORMAL,
-                    self.old_message_tv_color)
+                self.msg_textview.override_background_color(
+                    Gtk.StateType.NORMAL, self.old_message_tv_color)
                 return
             self.print_conversation(message, self.contact.jid,
                 encrypted=encrypted, xep0184_id=xep0184_id, xhtml=xhtml,
diff --git a/src/conversation_textview.py b/src/conversation_textview.py
index 880e7f635..a0d7b7125 100644
--- a/src/conversation_textview.py
+++ b/src/conversation_textview.py
@@ -240,7 +240,7 @@ class ConversationTextview(GObject.GObject):
         self.last_time_printout = 0
 
         font = Pango.FontDescription(gajim.config.get('conversation_font'))
-        self.tv.modify_font(font)
+        self.tv.override_font(font)
         buffer_ = self.tv.get_buffer()
         end_iter = buffer_.get_end_iter()
         buffer_.create_mark('end', end_iter, False)
diff --git a/src/dialogs.py b/src/dialogs.py
index 41a9c65c3..101e93159 100644
--- a/src/dialogs.py
+++ b/src/dialogs.py
@@ -2919,7 +2919,9 @@ class PopupNotificationWindow:
             GLib.markup_escape_text(title))
 
         # set colors [ http://www.pitt.edu/~nisg/cis/web/cgi/rgb.html ]
-        self.window.modify_bg(Gtk.StateType.NORMAL, Gdk.color_parse('black'))
+        color = Gdk.RGBA()
+        Gdk.RGBA.parse(color, 'black')
+        self.window.override_background_color(Gtk.StateType.NORMAL, color)
 
         # default image
         if not path_to_image:
@@ -2945,9 +2947,11 @@ class PopupNotificationWindow:
             bg_color = gajim.config.get('notif_status_color')
         else: # Unknown event! Shouldn't happen but deal with it
             bg_color = gajim.config.get('notif_other_color')
-        popup_bg_color = Gdk.color_parse(bg_color)
-        close_button.modify_bg(Gtk.StateType.NORMAL, popup_bg_color)
-        eventbox.modify_bg(Gtk.StateType.NORMAL, popup_bg_color)
+        popup_bg_color = Gdk.RGBA()
+        Gdk.RGBA.parse(popup_bg_color, bg_color)
+        close_button.override_background_color(Gtk.StateType.NORMAL,
+            popup_bg_color)
+        eventbox.override_background_color(Gtk.StateType.NORMAL, popup_bg_color)
         event_description_label.set_markup('<span foreground="black">%s</span>' %
             GLib.markup_escape_text(text))
 
@@ -3337,8 +3341,9 @@ class XMLConsoleWindow:
         self.enabled = True
         self.xml.get_object('enable_checkbutton').set_active(True)
 
-        self.input_textview.modify_text(
-            Gtk.StateType.NORMAL, Gdk.color_parse(color))
+        col = Gdk.RGBA()
+        Gdk.RGBA.parse(col, color)
+        self.input_textview.override_color(Gtk.StateType.NORMAL, col)
 
         if len(gajim.connections) > 1:
             title = _('XML Console for %s') % self.account
diff --git a/src/disco.py b/src/disco.py
index 47ded9094..05153188a 100644
--- a/src/disco.py
+++ b/src/disco.py
@@ -645,15 +645,18 @@ _('Without a connection, you can not browse available services'))
         textcolor = gajim.config.get_per('themes', theme, 'bannertextcolor')
         self.disconnect_style_event()
         if bgcolor:
-            color = Gdk.color_parse(bgcolor)
-            self.banner_eventbox.modify_bg(Gtk.StateType.NORMAL, color)
+            color = Gdk.RGBA()
+            Gdk.RGBA.parse(color, bgcolor)
+            self.banner_eventbox.override_background_color(Gtk.StateType.NORMAL,
+                color)
             default_bg = False
         else:
             default_bg = True
 
         if textcolor:
-            color = Gdk.color_parse(textcolor)
-            self.banner.modify_fg(Gtk.StateType.NORMAL, color)
+            color = Gdk.RGBA()
+            Gdk.RGBA.parse(color, textcolor)
+            self.banner.override_color(Gtk.StateType.NORMAL, color)
             default_fg = False
         else:
             default_fg = True
diff --git a/src/gajim.py b/src/gajim.py
index eb988a759..ee2cb73c8 100644
--- a/src/gajim.py
+++ b/src/gajim.py
@@ -193,7 +193,6 @@ if os.name == 'nt':
 warnings.filterwarnings('error', module='gtk')
 try:
     from gi.repository import GObject
-    GObject.threads_init()
     GObject.set_prgname('gajim')
     from gi.repository import Gtk
     from gi.repository import Gdk
@@ -464,13 +463,6 @@ if __name__ == '__main__':
     interface.run()
 
     try:
-        if os.name != 'nt':
-            # This makes Gajim unusable under windows, and threads are used only
-            # for GPG, so not under windows
-            Gdk.threads_init()
-            Gdk.threads_enter()
         Gtk.main()
-        if os.name != 'nt':
-            Gdk.threads_leave()
     except KeyboardInterrupt:
         print('KeyboardInterrupt', file=sys.stderr)
diff --git a/src/groupchat_control.py b/src/groupchat_control.py
index 12134a6df..a64d4bb56 100644
--- a/src/groupchat_control.py
+++ b/src/groupchat_control.py
@@ -1958,8 +1958,8 @@ class GroupchatControl(ChatControlBase):
                 self.last_sent_msg = msg
                 if self.correcting:
                     self.correcting = False
-                    self.msg_textview.modify_base(Gtk.StateType.NORMAL,
-                        self.old_message_tv_color)
+                    self.msg_textview.override_background_color(
+                        Gtk.StateType.NORMAL, self.old_message_tv_color)
 
             if self.correcting and self.last_sent_msg:
                 correction_msg = self.last_sent_msg
diff --git a/src/gtkexcepthook.py b/src/gtkexcepthook.py
index bb31bde4b..d448058d9 100644
--- a/src/gtkexcepthook.py
+++ b/src/gtkexcepthook.py
@@ -59,7 +59,7 @@ def _info(type_, value, tb):
     # Details
     textview = Gtk.TextView()
     textview.set_editable(False)
-    textview.modify_font(Pango.FontDescription('Monospace'))
+    textview.override_font(Pango.FontDescription('Monospace'))
     sw = Gtk.ScrolledWindow()
     sw.set_policy(Gtk.PolicyType.AUTOMATIC, Gtk.PolicyType.AUTOMATIC)
     sw.add(textview)
diff --git a/src/gui_interface.py b/src/gui_interface.py
index 5175f6996..f593f3a92 100644
--- a/src/gui_interface.py
+++ b/src/gui_interface.py
@@ -2591,7 +2591,7 @@ class Interface:
         sw = Gtk.ScrolledWindow()
         sw.set_policy(Gtk.PolicyType.AUTOMATIC, Gtk.PolicyType.AUTOMATIC)
         view = IPythonView()
-        view.modify_font(Pango.FontDescription(font))
+        view.override_font(Pango.FontDescription(font))
         view.set_wrap_mode(Gtk.WrapMode.CHAR)
         sw.add(view)
         window.add(sw)
diff --git a/src/ipython_view.py b/src/ipython_view.py
index 609f2b5a2..1da9f9300 100644
--- a/src/ipython_view.py
+++ b/src/ipython_view.py
@@ -349,7 +349,7 @@ class ConsoleView(Gtk.TextView):
         Initialize console view
         """
         GObject.GObject.__init__(self)
-        self.modify_font(Pango.FontDescription('Mono'))
+        self.override_font(Pango.FontDescription('Mono'))
         self.set_cursor_visible(True)
         self.text_buffer = self.get_buffer()
         self.mark = self.text_buffer.create_mark('scroll_mark',
diff --git a/src/tooltips.py b/src/tooltips.py
index c127dbfa1..c4977d3b1 100644
--- a/src/tooltips.py
+++ b/src/tooltips.py
@@ -151,7 +151,6 @@ class BaseTooltip:
 
         self.preferred_position = [pointer_x, preferred_y]
         self.widget_height = widget_height
-        self.win.ensure_style()
         self.win.show_all()
 
     def hide_tooltip(self):
@@ -678,7 +677,6 @@ class RosterTooltip(NotificationAreaTooltip):
             self.win.destroy()
             self.win = None
             self.populate(self.cur_data)
-            self.win.ensure_style()
             self.win.show_all()
 
     def _append_pep_info(self, contact, properties):