-The infinite button is for connecting other JBL speakers. I dont know how it works because this is my first JBL. But the manual says the JBL pulse 3 has to be playing music and the other JBL should be on. When you press the infinite button it should start to play the same music.-The light button has 8 light modes.
https://www.amazon.com/JBL-Pulse-Wireless-Bluetooth-Waterproof/dp/B074Q4S2NJ