To coordinate color of illumination by a luminaire with daylight for restricting generation of a sense of incongruity.

A device comprises a luminaire 1 installed inside a room to which daylight is incidental, and provided with two lamps 1a, 1b of different color temperatures, a daylight measuring part 2 to measure a color temperature of the daylight incidental on the room, and a lighting control part 5 to control a color temperature of the luminaire 1 by controlling flasing and dimming of the lamps 1a, 1b in accordance with the color temperature of the daylight. Between the daylight measuring part 2 and the lighting control part 5, a color coordination operation part 6 is provided to output a color coordination signal to the lighting control part 5 based on the input from the daylight measuring part 2 for setting the color temperature of the luminaire 1 to be lower than the color temperature of the daylight by a specified value within a range of 10-140 mired.