What is that light that flashes red/green by the sunroof control buttons. It's a 2000 ls v6 4x4.

 

Is this the ASC button?

I believe it stands for Automatic Sunroof Control. When it is turned on (green) it will automatically close your sunroof when you turn the key off and out of the ignition. If you it is off (red) it will leave the sunroof in the open position when you remove the key.

My sunroof was doing this yesterday after unplugging the battery and checking some fuses. To reset the light I opened the sunroof fully (you may have to hold down the open button to get it to move). Once fully open, depress the "open" button and the ASC light should have stopped flashing. Now it should work in its normal state.

Hope this helps!