After a long period of dark, almost black-stained wood floors, gray stains have begun surging in the Denver area over the past year, says Brian Park, founder and CEO of Lone Tree, Colo.-based Footprints Floors. Lighter floor colors are easier to maintain, he says. "Flooring trends tend to follow trends in paint colors," Park adds. "So, for the last 20 years we've seen a lot of beiges. Now what we've been seeing is that the Millennials who are purchasing homes and starting projects aren't wanting to copy their parents. There's been a transition from beiges and browns to grays."