The "power" LED on the CC18 is actually a red/green bi-colour LED which you can program for 8 different color and blinking.
It is programmed with the following sequence
SetU 0,LEDColour
SPxCmd1 2,!CPU
The value of LEDColour determines what you get, here are some SPLat equates, ready to use:
;LED Colours
LEDkOff EQU 0
LEDkGreen EQU 1
LEDkRed EQU 2
LEDkOrange EQU 3
LEDkRedGreen EQU 4
LEDkBlinkGreen EQU 5
LEDkBlinkRed EQU 6
LEDkBlinkOrange EQU 7
Note this feature does not apply to the CC16