The tail light bulb is just a standard 1157 (dual fillament). The top of the tail light is clear to light the licence plate but the rest of the lens is red. So, if you're just glancing back from the seat of your bike, you'll notice it is white, but if you are standing behind your bike, you should see red. However, if you are glancing back from the seat of your bike with the brake on, and you do not see any light then the bulb is burnt, likewise if you do not have the brake on and you see no light.
Soren
