The invention relates to a method for operating an illumination system (1) for an interior (31) of a vehicle (30), the illumination system (1) having a control unit (2) and an ambient illumination (10) with at least one lamp (11), which is designed to emit light in at least one ambient color (40). Furthermore, the invention relates to an illumination system (1) for illuminating an interior (31) of a vehicle (30), having an ambient illumination (10) with at least one lamp (11), which is designed to emit light in at least one ambient color (40), wherein furthermore at least one functional element (20) is arranged in the interior (31) of the vehicle (30), which has an element color (50) for displaying the functional element (20), as well as a vehicle (30) with an illumination system (1) for illuminating an interior (31) of the vehicle (30).