Abstract: A signal lamp having a housing in which a source of light is mounted, with the support surface being mounted in front of the light source. The support surface comprises the face plate of the signal lamp and has mounted thereon a pattern, symbol, or indicia which is displayed for the attention of an observer when the light source is inoperative. The pattern, symbol or indicia is of such a thickness that it reflects ambient light so as to be readable when the light source is inoperative, but thin enough to transmit the light field of the lamp so that the pattern, symbol or indicia is obscured when the light source is activated.