In this work, the photoluminescence of single InGaN NWs with a core-shell structure is investigated along their entire length at RT and 77 K. Multicolor emission, covering the spectral range from 380 to 650 nm, was obtained and described in details. Using the modified Vegard’s law, the photoluminescence lines were correlated with the InGaN composition. Based on these results, conclusions about the structural properties and homogeneity of the InGaN NWs along their length were carried out.