Controlling lighting devices

A method of controlling a lighting device by a controller, for the lighting device to produce illumination based on a reference spectral power distribution, the lighting device comprising a plurality of light channels with predefined spectral power distributions, a light mixer, and a colour sensor;

• the method comprising:
• determining, by the controller, first intensity adjustments of the light channels for minimizing a first spectral deviation between a first calculated spectral power distribution and the reference spectral power distribution, the first calculated spectral power distribution depending on the predefined spectral power distributions of the light channels and the first intensity adjustments;
• sending, by the controller, first control signals to the light channels for inducing the light channels to emit lights based on the first intensity adjustments;
• receiving, by the controller, sensor signals from the colour sensor representing colour coordinates of a mixture of lights resulting from interaction of the lights emitted by the light channels with the light mixer;
• performing, by the controller, an optimization process producing second intensity adjustments for minimizing a colour deviation between colour coordinates of reference and the colour coordinates of the mixture of lights;
• and
• sending, by the controller, second control signals to the light channels for inducing the light channels to emit lights based on the second intensity adjustments.