Monochromatization in the context of accelerator physics is a theoretical principle used to increase center-of-mass energy resolution in high-luminosity particle collisions. The decrease of the collision energy spread can be accomplished without reducing the inherent energy spread of either of the two colliding beams, introducing opposite correlations between spatial position and energy at the interaction point (IP). In beam-optical terms, this can be accomplished through a non-zero dispersion function for both beams of opposite sign at the IP. The dispersion is determined by the respective lattice.