Abstract: A fluorescent foil is formed from a translucent/transparent foil material having admixed therewith coloring matter and fluorescent matter. A translucent layer substantially impermeable to ultraviolet rays is provided on one side of the foil material. A translucent adhesive layer is also applied to the fluorescent foil, preferably to the translucent ultraviolet barrier layer. A sign board is formed on translucent/transparent substrate by attaching fluorescent foils so formed to opposite sides of the substrate. The translucent foils have different colors and are cut to the form of letters, figures, logograms, emblems, etc. in a complementary manner. The sign board may be illuminated by ultraviolet light from either or both sides to provide an attention getting, multi-color display.