An antidote to January’s inevitable post-holiday gray winter blahs: retina-pleasing vivid colors, now suddenly ubiquitous on everyday objects, like Post-it’s new yellow, blue, or green label pads ($5 to $25 at Office Depot, 1441 Broadway, nr. 41st St.; 212-764-2465), or the tropically bright blue and pink weekly planners by Ecosystem ($14.95 at Barnes & Noble, 33 E. 17th St., nr. Broadway; 212-253-0810). Here, Mario Bellini’s new Dune trays, made from heavy-duty resin and available in seven hues, including the violet and orange shown overlapping here ($113 each at Kartell, 39 Greene St., nr. Grand St.; 212-966-6665).