A quantum dot colloid, comprising a population of quantum dots dispersed in a nonconductive host matrix, each quantum dot having a substantially uniform surface energy, wherein the dots are of a size distribution, composition, or a combination thereof, selected to photoluminesce light of a spectral distribution of wavelengths characteristic of a selected color when the host matrix is irradiated with light from a primary source whose wavelength is shorter than the longest wavelength of said spectral distribution.