When you descend the staircase to the platforms at Columbus Circle, you may think you’ve fallen into an alternate Candy Land-like universe. Nope, this isn’t Oz. You’re staring at “Whirls and Twirls (MTA),” a mammoth tile installation designed by the late Sol LeWitt, which splatters vibrant colors onto the station’s belly. Sadly, on the day I visited, most riders didn’t seem to notice. I spied a group of tourists staring at it, then realized they weren’t marveling at the bright wall at all; they were trying to figure out the subway signs. But while many preoccupied commuters may be too busy with their BlackBerries to take in the spectacle, kids will definitely spot it. I watched as a grade-schooler stood mesmerized by the snaking, porcelain tiles as his grandmother desperately tried to yank him away to the Bronx-bound train. Pint-sized passengers certainly seem to respond to the fantastical piece. They’re not just taking a subway ride; they’re getting to go over the rainbow.