A lighting system for and method of commissioning LED light fixtures is disclosed. The LED light fixtures include a controller unit that is programmed with lighting firmware and an on-board 5 light sensor that is responsive to visible light signals from a light source. In operation, the light sensor is irradiated visible light signals and/or visible light sequences that instruct the LED light fixture via the controller unit to join a group, be locked into a group, run lighting programs and/or become un-locked from a group.