you'd need a sample of the color, chip/otherwise, when I volunteered at habitat for humanity before, I've mixed paint to match a color from someone's phone picture before :S can't guarantee the paint matches since the camera doesn't catch the color correctly but it might be the easiest if you don't have a sample of the color to :S and paint there is pretty cheap if you have one near you
is it an odd color? Could you replicate it pretty well using a paint kit then take that color in?