A LED operation light, comprising at least two power sources, at least one of which is an adjustable power source, at least two LED units, and measuring and control means. The LED units, which comprise one or more LED components, emit light in response to power received from the power source. The LED components have been arranged to produce emission of light color components of at least two different wavelengths. The measuring means have been arranged to measure light emission of the LED unit and, based on measurement data, to generate control information to be sent to the adjustable power source to adjust the magnitude of power to be supplied to the LED unit. The light emission of the LED component changes as the received power changes, which again results in a change in the correlation between the emitted light color components, and therefore in the color temperature.