A light generating system configured to generate system light in a first operational mode, wherein in the first operational mode: - the system light has a spectral power distribution with at least 85% of the spectral power in three emission bands comprising (i) a first emission band having a centroid wavelength of 445 nm +/- 25 nm and having a full width half maximum of at maximum 25 nm, (ii) a second emission band having a centroid wavelength of 541 nm +/- 25 nm and having a full width half maximum of at maximum 150 nm, and (iii) a third emission band having a centroid wavelength of 614 nm +/- 25 nm and having a full width half maximum of at maximum 25 nm; - the light generating system is configured to control the spectral power distribution of the system light in dependence of a radiant flux of the system light while maintaining a correlated color temperature of the system light within +/-10% of a predetermined correlated color temperature value; - the light generating system is configured to shift a color point of the system light towards a lower D uv when decreasing the radiant flux of the system light or to shift the color point of the system light towards a higher D uv when increasing the radiant flux of the system light ; the light generating system is configured to generate an illuminance selected from an illuminance range of at most 50 lux at a predetermined distance (d1) of a light emitting surface of the light generating system , wherein the predetermined distance (d1) is selected from the range of at most 20 m, and - the system light comprising white light having a correlated color temperature in the range of 1800 - 6500 K. - the system light has a spectral power distribution with at least 85% of the spectral power in three emission bands comprising (i) a first emission band having a centroid wavelength of 445 nm +/- 25 nm and having a full width half maximum of at maximum 25 nm, (ii) a second emission band having a centroid wavelength of 541 nm +/- 25 nm and having a full width half maximum of at maximum 150 nm, and (iii) a third emission band having a centroid wavelength of 614 nm +/- 25 nm and having a full width half maximum of at maximum 25 nm; - the light generating system is configured to control the spectral power distribution of the system light in dependence of a radiant flux of the system light while maintaining a correlated color temperature of the system light within +/-10% of a predetermined correlated color temperature value; - the light generating system is configured to shift a color point of the system light towards a lower D uv when decreasing the radiant flux of the system light or to shift the color point of the system light towards a higher D uv when increasing the radiant flux of the system light ; the light generating system is configured to generate an illuminance selected from an illuminance range of at most 50 lux at a predetermined distance (d1) of a light emitting surface of the light generating system , wherein the predetermined distance (d1) is selected from the range of at most 20 m, and - the system light comprising white light having a correlated color temperature in the range of 1800 - 6500 K. <EOS>