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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _assert_is_color(value):
 """ Assert that the given value is a valid brightness. :param value: The value to check. """

        if not isinstance(value, tuple) or len(value) != 3:
            raise ValueError("Color must be a RGB tuple.")

        if not all(0 <= x <= 255 for x in value):
            raise ValueError("RGB values of color must be between 0 and 255.")