I came across this site and though changing the lights on my speedometer would make the appearance a lot better. However, I don't know which bulb I need that would fit my 2003 Monte Carlo. Could someone please help me here.
Thank you ahead of time! Justin.

 

You will need to crack open your gauge cluster and solder in different colored LEDs. They arent just bulbs that you can pop out and replace.

 

I just finished modding all my interior lights to blue LED's. BBEngineering has an excellent description on how to mod the Instument Cluster. http://www.bbengineer.com/cars/impala/clusterlight.htm
I took it a step further and mounted the LED's flush to the board with the current limiting resistor on the back of the board to help keep the brightness uniform across the gauges. Don't know how to post pics but if you want to see them email me at usmcdevildogdfw@gmail.com