A lighting system controller, a lighting system control method and software program product are provided for controlling a lighting device based on a trigger signal, such as a presence detection signal from a presence sensor. Instead of switching the lighting device to a fixed light setting at all times when the trigger signal is received, the initial light output of the lighting device is determined. The lighting device is then controlled according to a fixed light setting (e.g. white light at full brightness) if the determined initial light output is within a predetermined range, and else it is controlled according to a function relative to the determined initial light output. For example, if the lighting device is participating in a romantic scene emitting predominantly red light the lighting device may switch to reddish white light instead of the full white light and/or the brightness level of the light is lowered compared to the fixed light setting.