A basic idea of the invention is to categorize color of light into groups on the basis of dominant wavelength. After the colors have been categorized into different groups, a particular group of colors may be selected on the basis of a predetermined criterion, one criterion being that an individual is to perceive the ambient temperature as higher than it actually is, while another criterion may be that the individual is to perceive the ambient temperature as lower than it actually is. Thereafter, a control signal is generated for controlling the dominant wavelength of light emitted from at least one light source in accordance with the selected group of colors. Finally, the generated control signal is transmitted to the light source(s) to be controlled, for emitting light of the selected group of colors, thereby influencing the thermoregulation of an individual being exposed to the light of the selected group of colors on the basis of the predetermined criterion. The present invention is advantageous, in that colored lighting is employed for changing an individual's perception of ambient temperature, which enables energy savings for heating and air conditioning systems. Using a lighting control device for varying color of light results in a flexible solution since the device easily facilitates changing to an environment that is perceived as warmer or as cooler than the actual room temperature.