i was always hated default gedit color.
and i knows there is tool like gtk-theme-switch2, but it is not enough to me.
so i had have to modify gedit(3.8.0) source myself.
git clone git://git.gnome.org/gedit
vi gedit-app.c +1148
static GeditWindow *
gedit_app_create_window_impl (GeditApp *app)
window = g_object_new (GEDIT_TYPE_WINDOW, “application”, app, NULL);
gedit_debug_message (DEBUG_APP, “Window created”);
//change it to your own color
+ GdkColor color;
+ gdk_color_parse(“#00284d”, &color); // http://www.colorhexa.com/00284d
+ gtk_widget_modify_bg(window, GTK_STATE_NORMAL, &color);
If gedit is not saving any changes you make in the Edit>Preferences menu