UNLIKE ORDINARY BULBS, LED bulbs are polarity sensitive; if the LED bulb does not work when installed, simply reverse the wiring of the base of the bulb.
Please note that this bulb is not suitable for use in a bi or tri-colour light
fitting. All LED’s work on a set colour frequency and if a white LED bulb
is placed behind a green lens the resulting light will be blue-ish and will
not fall within the permitted range of the collision regs. Similarly the red
light will be very dark and will not meet the visibility requirements.