An illuminated sign comprises a source of blue light; a quantum dot-containing film that produces green light when illuminated by the source of blue light; and, a patterned blue cutoff filter in optical communication with the quantum dot-containing film configured to allow a mixture of excess blue light from the source of blue light and green light from the quantum dot-containing film to pass through the pattern. The mixture of blue light and green light produces a pseudo white light. The illuminated sign may thus comprise pseudo white letters and/or graphics on a luminous green background.