IMHO, black is one of the best colors the g6 comes in. it looks hot.
For appearance modifications i suggest picking a color that will compliment or go well with the black of the car such as red, yellow, blue, pink, or anything else.
once u pick the color, the possibilities are endless.
decal overlays, caliper paint, dash trim kits/ custom paint, colored leds painting the engine cover, colored gauge face, etc.
jus look at sum of the members rides threads and u'll get sum good ideas.
i suggest looking at lampoon's, and crazy j's.
robert and justin have the most modifications done to thier cars.
if u find sumthing u like, ask around and sumone can tell u where to get it, or use the search, it may have been talked about in a previous thread.
btw, i have a blk 06 gtp vert, and i'm slowly working on adding purple accents, i have pics up in my thread.
have fun, and congrats on the new g6.