MODEOPTS BUFFER {DIRECTION} {BACK} {EDGE}
DIRECTION:
Direction of lightsource. One of, "E", "NE", "N", "NW", "W", "SW", "S" or "SE".
BACK:
Colour of background. Either "GREYBACK", or "COLOURBACK".
EDGE:
Colour of edges. Either "GREYEDGE", or "COLOUREDGE".