US Patent 7453218 Programmable dichromatic legend lighted switches

Illumination color for a dedicated legend display area of an illuminated pushbutton switch may be programmed by controlling application of the driving voltage to one of two or more different groups of interleaved LEDs alternately illuminating the display area. Each of the different LED groups illuminates the display area with a different color, produced by different color LEDs, filtering of individual LEDs within each group, or dip-coating the LEDs. Application of the driving voltage to different switch input pins causes the legend to be illuminated by different LED groups in different colors, reflecting different conditions.