A lighting device (18), e.g. for horticulture applications, comprises a planar array (180, 181, 182) of electrically-powered light radiation sources, e.g. LEDs, partitioned into a plurality of sets of light radiation sources. The light radiation sources of the same set emit light radiation of the same colour, and different sets of radiation sources emit light radiation of different colours (e.g. red, blue, deep red, white). The array (18) comprises a total number of light radiation sources with each one of the different sets of light radiation sources comprising a respective fraction of the total number of light radiation sources in the array (18). The light radiation sources have respective planar coordinates relative to a common centre (0) of the array (18), and the different sets of light radiation sources have respective centres located at the common centre (0) of the array (18). The array (18) comprises at least two complementary sub-arrays (181, 182), opposite to the common centre (0). The different sets of radiation sources are present in the sub-arrays (181, 182) in respective partial fractions of the number of radiation sources included in the sub-array. For each of the different sets, the respective partial fractions in the sub-arrays (181, 182) reflect (i.e. they are substantially equal to) the respective fraction of the total number of light radiation sources in the array the respective fraction of the total number of light radiation sources in the array (18).Dispositif d'éclairage (18), par exemple pour des applications d'horticulture, comprenant un réseau plan (180, 181, 182) de sources de rayonnement lumineux alimentées électriquement, par exemple des DEL, divisées en une pluralité d'ensembles de sources de rayonnement lumineux. Les sources de rayonnement lumineux du même ensemble émettent un rayonnement lumineux de la même couleur, et différents ensembles de sources de rayonnement émettent un rayonnement lumineux de différentes couleurs (par exemple
