Go ahead and dye it. There are lots of quality products out there that won't do a number on your hair, and the color can swell the hair shaft and give a fuller appearance.
I got my gray hair early too, in an odd streak over my left eyebrow--and not the cool Bonnie Raitt king of thing either. So yeah, I cover that up. I don't think it makes me look old--it just looks weird with my haircolor.