From Quake Wiki

New entity field:

.vector colormod;

colormod controls color of the entity, '0 0 0', is forced to be '1 1 1' (otherwise everything would be black), used for tinting objects, for instance using '1 0.6 0.4' on an ogre would give you an orange ogre (order is red green blue), note that in DarkPlaces, colors can go up to '8 8 8' (8x as bright as normal).