The results of measurements of the threshold current of ultraviolet, blue and green InGaN LEDs on different spectral components of the full emission spectrum are presented. It is shown that the threshold current of long-wave  components of the spectrum is greater than the threshold current of short-wave components. The relative difference in the values of the threshold current of the spectral components of the short-wave and long-wave wings of the emission spectrum at the level of half the radiation power is associated with the inhomogeneous distribution of indium concentration in the quantum well of the InGaN/GaN heterostructure and for the studied ultraviolet LEDs is 2.8%,  4.4% for blue, 25.7% for green.