code: func (l *RgbLedDriver) Off() (err error) {
  	if err = l.SetLevel(l.pinRed, 0); err != nil {
  		return
  	}
  
  	if err = l.SetLevel(l.pinGreen, 0); err != nil {
  		return
  	}
  
  	if err = l.SetLevel(l.pinBlue, 0); err != nil {
  		return
  	}
  
  	l.high = false
  	return
  }
docs: // Off sets the led to black.