Fogpal (DEF)
fogpal <palette number> <red> <green> <blue>
fogpal defines a palette a sector-based fog effect. To use it, change the pal of your sector to the pal defined with fogpal.
Intensities range from 0-63. Palettes 26, 27, 28 and 29 are pre-defined for you as white, red, green and blue respectively. Sector visibility controls fog density.
The palookup token has a subtoken also named fogpal which offers the same or more functionality, but as part of an overall more powerful command.