looking for the blue headlights

can i get the "blue headlights with just a bulb change? or is there more to it then that?

Yes you can get "blue" headlights by just changing the bulb. However, the lighting output may be reduced by the colored coating on the bulb. There are aftermarket HID kits availible but do not use them in a non-projector housing. All you will be doing is blinding other drivers. The only way to have true HID's in our trucks is to convert to the factory 98+ GMC Envoy headlights, bulbs w/ balasts, etc.