A lighting system includes a controlling device and a lighting device. The controlling device is configured to receive an electrical signal from mains electricity, enter a transition mode upon receiving a tuning signal, and enter a normal mode after a predetermined period of time has elapsed since a latest receipt of the tuning signal. The controlling device is further configured, in the normal mode, to continuously output the electrical signal as a control signal to the lighting device, and in the transition mode, continuously output a modified signal as the control signal to the lighting device.