A lighting device comprising a light source being configured to generate source light of a white light emission spectrum having a color correlated temperature (CCT) in a range of 2500-20000K and comprising a control unit being configured to control a lighting element for tuning of the source light with respect to a ratio between a first emission peak in a wavelength range of 460-490 nm and a second emission peak in a wavelength range of 430-460 nm. Thus a lighting device with a tunable/adjustable spectrum is provided that can switch between a first operation state of energy efficiency lighting with a blue peak in the second wavelength range of 430-460 nm, but with blue hazard risk, and a second operation state of less efficient but safe, healthy lighting with a biological stimulant having a blue peak in the first wavelength range of 460-490 nm.