Add calib function to EV3 Color sensor

lib/ev3/color.py

@@ -48,6 +48,7 @@ class ColorSensor(EV3UartSensor):
     MODE_COLOR = const(2)
     MODE_REFLECT_RAW = const(3)
     MODE_RGB_RAW = const(4)
+    MODE_COL_CAL = const(5)
 
     # calibration by JV
     DEFAULT_RGB_CALIBRATION = ColorSensorCalibration(275, 334, 242, 0, 0, 0)
@@ -187,3 +188,10 @@ class ColorSensor(EV3UartSensor):
             return code
         else:  # code == 0: COLOR_NONE => return None
             return None
+
+    def calibrate(self):
+        """
+        Calibrate the sensor's RGB components and save them to sensor memory.
+        """
+        self.read_raw_mode(ColorSensor.MODE_COL_CAL)
+