def RGB(nRed, nGreen, nBlue):
    """Return an integer which repsents a color.
       The color is specified in RGB notation.
       Each of nRed, nGreen and nBlue must be a number from 0 to 255.
    """
    return (int( nRed ) & 255) << 16 | (int( nGreen ) & 255) << 8 | (int( nBlue ) & 255)