First, dealerships are NOT your friend. Sales people are NOT your friends either. Their jobs are to get you into higher prices vehicles. I bet if there was an 5.7L Hemi available, the 3.5L would be toooooo small of an engine as well.
Drive the 2.5L Journey and see if it is adequate for you. If it has plenty of passing and merging power for you, get it. Don't let some sales person who isn't going to be making the payment sway you.
I've been looking for a color chart as well on the web and cannot find one