The number of colour indices used by FIT2D may be control by the -col option followed by the number of colour levels to be used. (-colours, -COLOURS, -COL, +COL, +COLOURS, etc are alternative accepted options.) FIT2D uses eight colours for the primary and secondary colour, and for black and white, and a variable number of colours for continuous false colour scale display of image data. The minimum number of colours is 16, whilst the maximum is presently 210. Values outside this range are ignored. Clearly colour tables with only eight colours (the minimum allowed) are not smooth.
This option can be useful to allow other programs which are not written to create their own colour tables to run after FIT2D has been started.
e.g. to start-up FIT2D using only 72 colour levels (64 used for the false colour image display) enter:
> fit2d -col72