[Therion] Change altitude colours

[Tarquin Wilton-Jones]

Hi Paul,

> /colour map-fg altitude/

Yes indeed, you can use a lookup table.

https://therion.speleo.sk/wiki/examples#colour_palette_scales_-_lookups
https://www.mail-archive.com/therion@speleo.sk/msg06798.html

Lookup tables allow you to do specific colouring by maps, or altitude.

I have never tried to use it with smooth colouring though, so have no 
idea how it interacts with that setting. I have only ever used it with:
smooth-shading off

Enjoy :)

Tarquin