A color cathode ray tube includes an in-line electron gun having a main lens with recessed apertures. The main lens is formed by two electrodes. These electrodes have outer edges and recessed apertures which allow passage of three in-line electron beams and which are arranged at a distance d1 and d2, respectively, from the outer edges. The outermost apertures are asymmetric. The difference d1-d2 and the asymmetry of the outermost apertures is such that both the beam displacement and the core haze asymmetry are minimal.