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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 set_special(index, color, iterm_name="h", alpha=100):
 """Convert a hex color to a special sequence."""

    if OS == "Darwin" and iterm_name:
        return "\033]P%s%s\033\\" % (iterm_name, color.strip("#"))

    if index in [11, 708] and alpha != "100":
        return "\033]%s;[%s]%s\033\\" % (index, alpha, color)

    return "\033]%s;%s\033\\" % (index, color)