The first time I went backpacking (as an adult), one of the girls on the trip told me to bring a comfortable dress. I was a little perplexed, but I brought my bright blue J.Crew loose-fitting dress. (I'd link you to me wearing it on backpacking trips if my ex-bf hadn't made them private :) Once we got to our camp-site all the girls busted out their dresses and started changing. Allow me pass on their infinite wisdom.
Scenario: you get to your campsite and want to change into your camp clothes.
Problem: it's too cold/you're too shy to strip down to your skivvies.
Solution: take off as many layers as you're comfortable with, then slip into the dress and change under the dress. BOOM.
I wish I still had my blue dress, but I took it on a trip to Russia and my aunt loved it so much that I had to leave it with her. So...I got to shop for another 'camp dress' for my backpacking trip next weekend!
P.S. I went with 'coral' :)