CAS555 is "drama" and I added some drama with a classic dark/light contrast- dark grey cardstock against cream.
I'm also playing along with a few other challenges:
CASology- fog (fog cardstock!)
CAS Watercolor- maple leaf
Just Us Girls- frame it
Sunday Stamps- color challenge (dark grey, medium grey, orange, & cream)
Shopping our Stash- pumpkin spice/fall