Emergency lighting

Emergency lighting is used on both UNSC and Covenant starships or installations when the main power is down or during battle. Emergency lighting is usually powered by a separate generator so that it does not draw off the main reserves. The color of the light is usually redHalo: Combat Evolved - The Pillar of Autumn but can sometimes be yellow or orangeHalo 2 - Cairo Station with Covenant ships using ultraviolet for its emergency lighting.Halo: Ghosts of Onyx, Page 194 It is most essential that these lightings are used on the bridge, as combat situations will quickly get worse if you can't see what is going on. 
An example of this is seen on the bridge of the during the Battle of Installation 04.
==Appearances==
*Halo: The Fall of Reach 
*Halo: Combat Evolved
**Halo: Combat Evolved Anniversary
*Halo 2
**Halo 2: Anniversary
*Halo: The Flood
*Halo: First Strike
*Halo: Ghosts of Onyx
==Sources==