London-based designer Héctor Serrano—who constructed a dome of beach-ball-like color-changing LED orbs for this year’s Coachella music festival—once again plays to his inner child with these Submarino bathroom accessories ($70 at Beam, 240 Kent Ave., at N. 1st St., Ste. 18, Williamsburg; 917-434-2302). Made of rubber-coated porcelain for enhanced traction on sudsy surfaces, the four individual pieces—soap dispenser, toothbrush holder, and two catch-alls sized for anything from cotton balls to emergency Advil—are magnetized so that they can form a single yellow (or blue, or red, or white) submarine.