This article explains how FortiAPs can be kept as discrete as possible by using an option to run dark by turning off all LEDs.Scope
FortiOS v5.2 patch4.Solution
This can be configured in CLI:
config wireless-controller wtp-profile
set led-state enable|disable
By default, led-state is set to enable.
On the FortiAP side:
cfg -a LED_STATE=0|1|2
0:LED is on, 1:LED is off, 2: LED is controlled by the controller (FortiGate).
By default, LED_STATE is set to 2.
If it is set to 2, FortiAP will take led-state setting configured on the controller. If it is set to 0 or 1, FortiAP will ignore led-state setting configured on the controller.