Boss Steel Polyester designed by Nevotex. Cover for IKEA EKTORP three-seat sofa - Boss Steel. Neutrals (black, grey, white, and brown) are basic to the decorator’s tool kit. All-neutral schemes fall in and out of fashion, but their virtue lies in their flexibility: add color to liven things up; subtract it to calm things down. Neutral colours such as grey will blend with any décor, complement a more prominent color, and are easy to use.