Color Sensor TCS230 Extension for mBlock
This is a simple wrapper around Arduino samples for this sensor.
Here is an example Arduino code: http://howtomechatronics.com/tutorials/arduino/arduino-color-sensing-tutorial-tcs230-tcs3200-color-sensor/
And as explained there, values for the detected colors drop in the sensor readings. For example, if you bring a red colored object in front of the sensor, the red readings will drop. In the above link, this is explained right above the image where the author is holding a red paper in front of the sensor.
This extension works both with Arduino and Scratch modes.