Recently, reported on the concept of multicolor molecular imaging, which uses resonant light-scattering spectroscopy of multilayer nanospheres. They claimed that the resonance scattering peaks of three-layer nanoshells can be designed so that the ultrasharp widths are as narrow as . Here we show that such ultrasharp labels cannot be fabricated in reality because the effects of size-dependent dielectric functions result in the five- to tenfold broadening of resonant scattering peaks. Furthermore, contrary to the data of Chen et al. , we did not find any significant advantages of three-layer structures, as compared with the usual silica/metal nanoshells.