diff --git a/homeassistant/components/light/mqtt.py b/homeassistant/components/light/mqtt.py
index 97624ec72f9..30f968d758f 100644
--- a/homeassistant/components/light/mqtt.py
+++ b/homeassistant/components/light/mqtt.py
@@ -18,7 +18,6 @@ DEFAULT_NAME = "MQTT Light"
 DEFAULT_QOS = 0
 DEFAULT_PAYLOAD_ON = "on"
 DEFAULT_PAYLOAD_OFF = "off"
-DEFAULT_RGB_PATTERN = "%d,%d,%d"
 DEFAULT_OPTIMISTIC = False
 
 DEPENDENCIES = ['mqtt']
@@ -137,9 +136,8 @@ class MqttLight(Light):
 
         if ATTR_RGB_COLOR in kwargs and \
            self._topic["rgb_command_topic"] is not None:
-            rgb = DEFAULT_RGB_PATTERN % tuple(self._rgb)
             mqtt.publish(self._hass, self._topic["rgb_command_topic"],
-                         rgb, self._qos)
+                         "{},{},{}".format(*kwargs[ATTR_RGB_COLOR]), self._qos)
 
             if self._optimistic_rgb:
                 self._rgb = kwargs[ATTR_RGB_COLOR]
@@ -147,8 +145,10 @@ class MqttLight(Light):
 
         if ATTR_BRIGHTNESS in kwargs and \
            self._topic["brightness_command_topic"] is not None:
+
             mqtt.publish(self._hass, self._topic["brightness_command_topic"],
-                         self._brightness, self._qos)
+                         kwargs[ATTR_BRIGHTNESS], self._qos)
+
             if self._optimistic_brightness:
                 self._brightness = kwargs[ATTR_BRIGHTNESS]
                 should_update = True
diff --git a/tests/components/light/test_mqtt.py b/tests/components/light/test_mqtt.py
index bc0195feff1..8172a6c7c63 100644
--- a/tests/components/light/test_mqtt.py
+++ b/tests/components/light/test_mqtt.py
@@ -149,9 +149,7 @@ class TestLightMQTT(unittest.TestCase):
                 'platform': 'mqtt',
                 'name': 'test',
                 'command_topic': 'test_light_rgb/set',
-                'brightness_state_topic': 'test_light_rgb/brightness/status',
                 'brightness_command_topic': 'test_light_rgb/brightness/set',
-                'rgb_state_topic': 'test_light_rgb/rgb/status',
                 'rgb_command_topic': 'test_light_rgb/rgb/set',
                 'qos': 2,
                 'payload_on': 'on',
@@ -177,3 +175,26 @@ class TestLightMQTT(unittest.TestCase):
                          self.mock_publish.mock_calls[-1][1])
         state = self.hass.states.get('light.test')
         self.assertEqual(STATE_OFF, state.state)
+
+        light.turn_on(self.hass, 'light.test', rgb_color=[75, 75, 75],
+                      brightness=50)
+        self.hass.pool.block_till_done()
+
+        # Calls are threaded so we need to reorder them
+        bright_call, rgb_call, state_call = \
+            sorted((call[1] for call in self.mock_publish.mock_calls[-3:]),
+                   key=lambda call: call[0])
+
+        self.assertEqual(('test_light_rgb/set', 'on', 2, False),
+                         state_call)
+
+        self.assertEqual(('test_light_rgb/rgb/set', '75,75,75', 2, False),
+                         rgb_call)
+
+        self.assertEqual(('test_light_rgb/brightness/set', 50, 2, False),
+                         bright_call)
+
+        state = self.hass.states.get('light.test')
+        self.assertEqual(STATE_ON, state.state)
+        self.assertEqual([75, 75, 75], state.attributes['rgb_color'])
+        self.assertEqual(50, state.attributes['brightness'])