Normally, it would be contraindicated to take a marker to your dress. Not so with Color-in-Clothing, which you'll actually want to mark up. That's the way you give it color and infuse it with your own sense of style.
We're waiting to find out if and where the striking dress in the photos can be purchased, and if you can safely remove the markings if you're considering a whole new look.
Do note that you'll want to use a fabric marker rather than, say, a highlighter pen or your kids' crayons. Just be sure to color inside the lines--or not, if that's more in keeping with with your fashion aesthetic.
(Update 9:59 a.m. PDT: Soepboer tells us the dress isn't yet available for purchase, but should be soon. We'll keep you posted!)