The light-current characteristics of ultraviolet, blue, and green LEDs based on InGaN/GaN heterostructures were measured in different regions of the emission spectrum with a spectral resolution of approximately 1.5 nm. Based on the results of measuring and approximating the light-current characteristics with various functions, the threshold current, the current value at which the maximum internal quantum efficiency is reached, and the parameter determining the degree of nonlinearity of the light-current characteristic in the low-current range were determined. It was found that for ultraviolet LEDs, all three parameters depend weakly on the emission spectrum wavelength. For green and blue LEDs, these parameters differ in the short- and long-wavelength regions of the spectrum, and this difference is greater for green LEDs than for blue LEDs. Differences in the parameters of LEDs of different emission colors based on InGaN/GaN heterostructures with quantum wells are explained by differences in concentrations and the nonuniform distribution of indium in the quantum wells of the heterostructure. Keywords: LED heterostructure, emission spectra, light-current characteristics, threshold current, current of maximum quantum efficiency.