Abstract: Across the screen is a mosaic of spaced phosphor bodies which emit light of different colors when excited by electrons. Phosphors which emit three different colors, e.g. red, green and blue, are used and are disposed in a regular repetitive array of groups of three, i.e. triads. In every other triad the phosphor body which emits the color which has the least acuity to the eye, e.g. blue, is replaced by a nonluminescent black material. The blue phosphor bodies are of a width substantially equal to the width of the penumbra of the electron beam which impinges on the blue phosphor bodies. The red and green emitting phosphor bodies are of a width substantially equal to the umbra of their corresponding electron beams which is about one-half the penumbra of the beams.