I'd say that red light indicates that the immobolizer is active. At least in continental European models alarm is not standard, but red led is.
P.157 of the online handbook (at least for UK spec cars):
"■ When the security system alarm sets:
The security system alarm indicator in the instrument panel blinks. When the
blinking interval changes after about 15 seconds, the security system alarm is set."
There's no similar comment for the immobiliser, although I guess the light could apply to both. Anyway, the OP specifically asked about visual indication for the alarm.