Colored light chain circuit with adjustable flashing frequency of each group of colored lights

Only three groups of colored lights are drawn here. In fact, there can be multiple groups. Adjusting the potentiometers
(RPi~RP3) of each group can make each group of colored lights emit light at different frequencies, so the lighting effect is more interesting. In addition, if only one
group is used, the bulb can also be used as a light signal (such as flashing traffic lights), and its flash frequency can be adjusted as needed.