Speaking of her new colorscape at the Hamburger Bahnhof, the German artist Katharina Grosse says simply, “I painted my way out of the building.” She means that literally. Grosse’s kaleidoscopic streams of color stretch from the museum’s Historic Hall to the outdoor space behind the structure. Natural and manmade forms blend into each other as Grosse, with paint, veils the vertices of the museum’s architecture to breathtaking effect. —E.C.