diff --git a/homeassistant/components/light/mqtt.py b/homeassistant/components/light/mqtt.py
index 1e5c0f743bb..0348af664a5 100644
--- a/homeassistant/components/light/mqtt.py
+++ b/homeassistant/components/light/mqtt.py
@@ -424,7 +424,7 @@ class MqttLight(Light):
 
             tpl = self._templates[CONF_RGB_COMMAND_TEMPLATE]
             if tpl:
-                colors = {'red', 'green', 'blue'}
+                colors = ('red', 'green', 'blue')
                 variables = {key: val for key, val in
                              zip(colors, kwargs[ATTR_RGB_COLOR])}
                 rgb_color_str = tpl.async_render(variables)
diff --git a/tests/components/light/test_mqtt.py b/tests/components/light/test_mqtt.py
index db7c35107d8..b074c5d84d8 100644
--- a/tests/components/light/test_mqtt.py
+++ b/tests/components/light/test_mqtt.py
@@ -546,17 +546,17 @@ class TestLightMQTT(unittest.TestCase):
         state = self.hass.states.get('light.test')
         self.assertEqual(STATE_OFF, state.state)
 
-        light.turn_on(self.hass, 'light.test', rgb_color=[255, 255, 255])
+        light.turn_on(self.hass, 'light.test', rgb_color=[255, 128, 64])
         self.hass.block_till_done()
 
         self.mock_publish().async_publish.assert_has_calls([
             mock.call('test_light_rgb/set', 'on', 0, False),
-            mock.call('test_light_rgb/rgb/set', '#ffffff', 0, False),
+            mock.call('test_light_rgb/rgb/set', '#ff8040', 0, False),
         ], any_order=True)
 
         state = self.hass.states.get('light.test')
         self.assertEqual(STATE_ON, state.state)
-        self.assertEqual((255, 255, 255), state.attributes['rgb_color'])
+        self.assertEqual((255, 128, 64), state.attributes['rgb_color'])
 
     def test_show_brightness_if_only_command_topic(self):
         """Test the brightness if only a command topic is present."""
diff --git a/tests/components/light/test_mqtt_template.py b/tests/components/light/test_mqtt_template.py
index a28d862bf53..4cda6fc64de 100755
--- a/tests/components/light/test_mqtt_template.py
+++ b/tests/components/light/test_mqtt_template.py
@@ -145,12 +145,12 @@ class TestLightMQTTTemplate(unittest.TestCase):
 
         # turn on the light, full white
         fire_mqtt_message(self.hass, 'test_light_rgb',
-                          'on,255,145,123,255-255-255,')
+                          'on,255,145,123,255-128-64,')
         self.hass.block_till_done()
 
         state = self.hass.states.get('light.test')
         self.assertEqual(STATE_ON, state.state)
-        self.assertEqual([255, 255, 255], state.attributes.get('rgb_color'))
+        self.assertEqual([255, 128, 64], state.attributes.get('rgb_color'))
         self.assertEqual(255, state.attributes.get('brightness'))
         self.assertEqual(145, state.attributes.get('color_temp'))
         self.assertEqual(123, state.attributes.get('white_value'))