Pillow Case Dress and a Giveaway!

I'm going to make a pillow case dress for each of my girls. I bought some fabric on sale forever ago and have only used a little bit. Then I found some other that I really like. I want to use both of them, but I'm not sure they look alright together.

the fabric

quick (horrible) sketch that shows which fabric will be used where
I hope it makes sense. It did in my head...

So the straps, the pocket, and the lining on the bottom will be from fabric b, but the main body will be fabric a. Do they clash too much? I don't like matchy fabrics, but I don't want my girls to look like I ate fabric and threw it up. Know what I mean?

Opinions? Suggestions? Free dinners? I'll take anything, really.