def is_valid_hcl(value: str) -> bool:
    """
    Return if value is a valid hcl (hair color).

    Parameter
    ---------
    value: str
        a hcl.

    Return
    ------
    bool
        True if hcl is valid, False othewise.
    """
    if value[0] != "#":
        return False
    return all((char.isdigit() or char in "abcdef" for char in value[1:]))