Before and After: A Poorly Laid Out Apartment's Colorful, Clever Reno Is Amazing

"As soon as my husband and I got the keys, we began the hard work," begins Justine Guillermou, the founder of Rainbow Shaker, who specializes in "playful, offbeat," and "anti-gloom" designs. "We did everything ourselves from A to Z, except for the plumbing and electricity."