diff --git a/addons/web/static/src/js/views/calendar/calendar_model.js b/addons/web/static/src/js/views/calendar/calendar_model.js
index e8e2b245369..8de8fd1f8c3 100644
--- a/addons/web/static/src/js/views/calendar/calendar_model.js
+++ b/addons/web/static/src/js/views/calendar/calendar_model.js
@@ -542,6 +542,7 @@ return AbstractModel.extend({
             });
 
             var fs = [];
+            var undefined_fs = [];
             _.each(events, function (event) {
                 var data =  event.record[fieldName];
                 if (!_.contains(['many2many', 'one2many'], field.type)) {
@@ -551,15 +552,18 @@ return AbstractModel.extend({
                 }
                 _.each(data, function (_value) {
                     var value = _.isArray(_value) ? _value[0] : _value;
-                    fs.push({
+                    var f = {
                         'color_index': self.model_color === (field.relation || element.model) ? value : false,
                         'value': value,
-                        'label': fieldUtils.format[field.type](_value, field),
+                        'label': fieldUtils.format[field.type](_value, field) || _t("Undefined"),
                         'avatar_model': field.relation || element.model,
-                    });
+                    };
+                    // if field used as color does not have value then push filter in undefined_fs,
+                    // such filters should come last in filter list with Undefined string, later merge it with fs
+                    value ? fs.push(f) : undefined_fs.push(f);
                 });
             });
-            _.each(fs, function (f) {
+            _.each(_.union(fs, undefined_fs), function (f) {
                 var f1 = _.findWhere(filter.filters, f);
                 if (f1) {
                     f1.display = true;
diff --git a/addons/web/static/tests/views/calendar_tests.js b/addons/web/static/tests/views/calendar_tests.js
index 198fd8a9d99..b6bebc0f4a2 100644
--- a/addons/web/static/tests/views/calendar_tests.js
+++ b/addons/web/static/tests/views/calendar_tests.js
@@ -146,7 +146,19 @@ QUnit.module('Views', {
     };
 
     QUnit.test('simple calendar rendering', function (assert) {
-        assert.expect(22);
+        assert.expect(24);
+
+        this.data.event.records.push({
+            id: 7,
+            user_id: session.uid,
+            partner_id: false,
+            name: "event 7",
+            start: "2016-12-18 09:00:00",
+            stop: "2016-12-18 10:00:00",
+            allday: false,
+            partner_ids: [2],
+            type: 1
+        });
 
         var calendar = createView({
             View: CalendarView,
@@ -187,7 +199,7 @@ QUnit.module('Views', {
         assert.strictEqual($sidebar.find('.o_selected_range').length, 1, "should highlight the target day in mini calendar");
 
         calendar.$buttons.find('.o_calendar_button_month').trigger('click'); // display all the month
-        assert.strictEqual(calendar.$('.fc-event').length, 6, "should display 6 events on the month (5 events + 2 week event - 1 'event 6' is filtered)");
+        assert.strictEqual(calendar.$('.fc-event').length, 7, "should display 7 events on the month (5 events + 2 week event - 1 'event 6' is filtered + 1 'Undefined event')");
         assert.strictEqual($sidebar.find('.o_selected_range').length, 31, "month scale should highlight all days in mini calendar");
 
         // test filters
@@ -196,15 +208,19 @@ QUnit.module('Views', {
 
         var $typeFilter =  $sidebar.find('.o_calendar_filter:has(h3:contains(user))');
         assert.ok($typeFilter.length, "should display 'user' filter");
-        assert.strictEqual($typeFilter.find('.o_calendar_filter_item').length, 2, "should display 2 filter items for 'user'");
+        assert.strictEqual($typeFilter.find('.o_calendar_filter_item').length, 3, "should display 3 filter items for 'user'");
+
+        // filters which has no value should show with string "Undefined" and should show at the last
+        assert.strictEqual($typeFilter.find('.o_calendar_filter_item:last').data('value'), false, "filters having false value should be displayed at last in filter items");
+        assert.strictEqual($typeFilter.find('.o_calendar_filter_item:last > span').text(), "Undefined", "filters having false value should display 'Undefined' string");
 
         var $attendeesFilter =  $sidebar.find('.o_calendar_filter:has(h3:contains(attendees))');
         assert.ok($attendeesFilter.length, "should display 'attendees' filter");
         assert.strictEqual($attendeesFilter.find('.o_calendar_filter_item').length, 3, "should display 3 filter items for 'attendees' who use write_model (2 saved + Everything)");
         assert.ok($attendeesFilter.find('.o_field_many2one').length, "should display one2many search bar for 'attendees' filter");
 
-        assert.strictEqual(calendar.$('.fc-event').length, 6,
-            "should display 6 events ('event 5' counts for 2 because it spans two weeks and thus generate two fc-event elements)");
+        assert.strictEqual(calendar.$('.fc-event').length, 7,
+            "should display 7 events ('event 5' counts for 2 because it spans two weeks and thus generate two fc-event elements)");
         calendar.$('.o_calendar_filter .o_checkbox input').first().click();  // Disable first filter
         assert.strictEqual(calendar.$('.fc-event').length, 4, "should now only display 4 event");
         calendar.$('.o_calendar_filter .o_checkbox input').eq(1).click();  // Disable second filter