Not sure about the voltage, I got the only blue one available from the RS I stopped at.
If you don't have the sunroof, it's not quite that simple. You need to get under the headliner.

 

does anyone know the RC part number for the blue light

 

Never made a note of it, and the packaging is loooooonnnnnng gone.

 

Thanks, Anyone else have the part number

 

I believe the part number you are looking for is 276-316, 5MM Blue LED, 3.7 volt, 20ma, 2600mcd.

The other blue available from RS is 276-311, 5MM Blue LED, 5 volt, 30ma, 300mcd. I tried this one first and found it to be too dim. Nice mood light but not much light on the controls.

 

The 276-316 5MM 3.7 volt is the right one. I installed it in mine and it works great, and adds a nice blue glow at night making it very easy to see the waterfall and window switches.

 

That's the one!!! good stuff!!

 

Thanks everyone for the response, I'm going to go buy the 276-316 tomrrow. Who can give good instructions on how to remove the light from the headliner. I have NO sunroof or On-Star just the light.
Thanks ahead of time

 

Found this after a very lengthy thread search..........

 

Since you don't have a sunroof you have to accesss the bulb from the top of the headliner, which involves removing a pillars and visors, and pulling GENTLY down on the headliner. You have to be very carefull as the foam board behind the headliner will break. Just pull it down far enough to get your hand back there. The wire harness is glued to the top of the headliner board also, and I had to remove it to access the bulb. Once you get your hand back there you will feel a stiff wire, just feel for the tip and pull it back towards the front of the car, and the bulb pops right out. You will have to trim the new bulbs wires, just trim to match the legnth of the old bulb. Make sure you put the new bulb in the right way. If it's backwards it won't work, and could pop. Good luck and just be carefull. It's not a tough job, but you have to take your time. Hope it helps.