Quote Originally Posted by Rythmic
I don't like Purpgrab, but you can try it beware though you may get some strange results.

Basically it is a side affect of Readbif, however:

It is possible, basically cover the places black dots appear with the background colour (a brown parchment colour). This will solve it.

Maybe R'as al Ghul has a better solution.
In effect I got strange results with Purpgrab: original palette missing by the way and image resized. Your suggestion is interesting, I'll try it. Very nice building icons for the Britannia Divided Mod

Quote Originally Posted by R'as al Ghul
Most of the problems are connected to a wrong palette. That's the main difficulty. When in doubt you can always load a working lbm or bif and check out the palette values. You can also, using photoshop, export a palette and import it again.
Hope that helps?
I've followed the instructions of DukeJohn in a quite free way and perhaps I made a mistake. I actually follow these steps:

1. With Readbif export a bmp from the bif that I'll use as model
2. With a painting program (I use the Gimp, a freeware program) I make the new image and save it preserving the original 256 colour palette.
3. With Readbif import the bmp to create a new bif (of course with black dots ).
4. Open again the new bmp with the Gimp and change the background colour from 0,128,0 to 207,207,199 (the background colour that uses the lbm file). Save it as bmp (the Gimp don't work with lbm).
5. And finally save this image as lbm with Ultimate Paint. Result: the faction colours don't appear in the game. I suspect that the problem is in this step, probably if I load an original MTW lbm palette with Ultimate Paint I'll see the proper faction colours in the game.

Many thanks for your help and patience, Rythmic and R'as al Ghul