def clip_colours(colour_value):
    """ This function ensures that our auto white balance module does not
    exceed the limits of our RGB spectrum.

    :param colour_value: The value of our colour channel.
    :return: The normalised value of our colour channel.
    """

    if colour_value <= 0:

        # Value of 0 is absolute black and cannot go lower.
        value = 0

    elif colour_value >= 255:

        # Value of 255 is absolute white and cannot go higher.
        colour_value = 255

    # Value must be whole number.
    return round(colour_value)