The color probably won't fade out in an appreciable way. I think that fit ought to come before color, and even then, the nature of deals is that they tend to resurface from time to time. If you're patient, you could probably compromise less.
When I can't hem my pants myself or get someone I know to them them for me for free, I usually spend 10 dollars on a hem job. Also, it should be noted: The hemming is done in Queens. I think anything from that to 20 or so is reasonable.