The white power indicator LED on the smart device is incredibly bright and does not turn off when the PC is powered down unlike the other LEDs attached to the device.
The only way to turn off the power indicator LED is to remove all power from the PC (Turn off the PSU), but this isn't feasible as removing power from the smart device also clears its cache, requiring you to start NZXT CAM after booting.
In my opinion the fact that the smart device caches the current config on the device as long as it doesn't lose power is one of the nicest things about it because it doesn't require further software to be ran at boot.
Currently the only other work around is to tape over the LED or desolder it.