X_AMBIENT_LT num#, col#
Turns on an ambient light (a light source that comes from every direction).
num# specifies the id of the light. OpenGL supports 8 different light sources of various types (ambient/spot light), so values of 0-7 are valid.
col# specifies the color of the light source. See RGB().
There is no intensity setting for an ambient light source.
There is not a lot of point in multiple ambient light sources so it is suggested that you use one light for an ambient light source and the rest (if necessary) for spotlights.
Due to the load light sources put on your system, the use of more than 2 light sources (either ambient or spot) is not recommended.
If you wanted to turn off the ambient light source, you could do so by using the command X_SPOT_LT num#,0,0,0,0,0,0,0,0 - where num# is the light number of the ambient light.