A color display device comprising at least two substrates spaced from each other, the substrates each having an internal and an external surface, the internal surfaces of the two substrates facing each other, at least one of the substrates being transparent; electrodes positioned to establish a field in the space between the two substrates; an optically active material occupying at least a portion of the space between the two substrates and having optical properties influenced by the field; a color filter layer comprising color filter elements that alter the color of light traveling through the color filter layer, the color filter elements being positioned outside of the space between the two substrates; and a three-dimensional black mask comprising mask elements aligned with the boundaries between adjoining color filter elements. The three-dimensional black mask structure allows the color filter to be placed on the exterior of the display while still maintaining good color performance under off-axis viewing conditions.