function argbFromLstar(lstar) {
    const y = yFromLstar(lstar);
    const component = delinearized(y);
    return argbFromRgb(component, component, component);
}
Converts an L* value to an ARGB representation.

@param lstar L* in L*a*b*
@return ARGB representation of grayscale color with lightness
matching L*