Depending on what country you live in it may be opposite with the hot/neutral wires. I'm in the U.S. and our wiring is opposite of China in terms of colors. (Here traditionally black is the hot wire; in China red is traditionally the hot wire.) This is for the buttons though.
The terms of hot and neutral only apply to AC. And yes different countries use different color codes. The encoders don’t use AC, but DC (the joystick switches can pass either or ).When it comes to DC, the standard everywhere, as far as I know, is red for positive and black for negative/dc ground. Just look at a car battery