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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 derivative_colors(colors):
 """Return the names of valid color variants, given the base colors."""

    return set([('on_' + c) for c in colors] +
               [('bright_' + c) for c in colors] +
               [('on_bright_' + c) for c in colors])