Cheap usb cable with light effect did not work reliably anymore (short service life cheap Chinese crap) so it is teardown time.
Inside I see three LEDs and plastic fiber optic cables connected to those LEDs. Those fiber optic cables are here not for fast data transfer fiber optic is usually known for. They are are here just purely for some (not so good) visual effect.
There seems to be some unmarked 6 pin chip that handles the LED controlling for the light show.