RGB code with Touchosc

In the setup put the line:
Serial.begin(9600); // serial debugging port
Unless your serial is already being used by
arduino = new Arduino(this, Arduino.list()[1],57600);

  //write to arduino
  arduino.analogWrite(11, int(redAmount));
  arduino.analogWrite(10, int(greenAmount));
  arduino.analogWrite(9, int(blueAmount));

  Serial.print(int(redAmount));
  Serial.println(" redAmount"); 
  Serial.print(int(greenAmount));
  Serial.println(" greenAmount"); 
  Serial.print(int(blueAmount));
  Serial.println(" blueAmount");  
}