Traceback (most recent call last):
  File "time.py", line 49, in <module>
    lcd.backlight(change_color(color))
  File "/home/pi/Adafruit-Raspberry-Pi-Python-Code/Adafruit_CharLCDPlate/Adafruit_CharLCDPlate.py", line 417, in backlight
    c          = ~color
TypeError: bad operand type for unary ~: 'str'