An improved LED light bulb for use in a brake light bulb socket of an automobile or similar vehicle wherein selected numbers of LED are energized at full intensity depending upon whether the automobile is in the brake light mode or the tail light mode. The light emitting diode lamp includes first and second printed circuit boards having first and second pluralities of light emitting diodes mounted thereupon for emitting monochromatic light in response to power signals supplied from the automobile. All LED's are on full intensity in the brake light mode and less than the full number of LED's on the first and second printed circuit boards are on at full intensity for the tail light mode.