If I recall correctly, the GROUNDxO.DAT files have four palettes in them; one used for the preview screen and one used during the game for both EGA and VGA.
The extractor script I wrote for Tundra lets you export PNGs of all the graphics using whatever colour scheme you want. Unfortunately, since it was released the Python guys deprecated the XML SAX library the game uses for just about frigging everything, and because of all the wide-eyed (read: crap) design decisions, I have little interest in touching the code without the aid of a long pointed stick.
That said, here's a stripped down version of the script I used. Go get
Python 2.6 and
PIL, then download
this package. Extract it somewhere, then run the Python interpreter and type in the following:
>>> import os
>>> os.chdir("c:\\path\\to\\where\\you\\put\\lemresgrab\\")
>>> from decrunchedit import *
>>> fullAuto("c:\\path\\to\\lemmings1\\", PALETTE)
(where PALETTE is one of "ega", "ega_prev", "vga", "vga_prev")
>>> fullAutoONML("c:\\path\\to\\onml\\", PALETTE)
This will dump all of the Lemmings graphics as PNGs into the included "style" folder. Hope this helps.
(For the two people that care, the Tundra site has been dead due to my ultra-reliable webhost repasswording my SQL database every two weeks
I just finished my thesis, so next project is to port LemmingsDS to the N900...)