Ok thanks for your input on this subject.
Yes I would be happy to provide an "export map (char) cell colour data" option.
This would export a block of colour data of equal size to the map (in chars) by simply translating each map cell into a colour depending on the contained char.
The thing I really want to avoid is adding "per map cell" (and "per tile cell") as basic colouring methods as this would really complicate things and demand a whole world of new converters and design features to be added.
So you would have to settle for the existing colouring methods at design time and just use the export option when needed.
I imagine this would mainly be used from the "per char" colouring method, so after exporting the colour map you could switch to "per project" and compress any differently coloured duplicates out of the char set and then export the (optimized) chars/map.
If you understand this I will try and get this option into the next update.