These are "renders" of the FLG files that come on the Dungeon Keeper disc. These files aren't used at all by the actual game, but seem to be some early type of level format for column data, since they are a 256x256, 3 times larger than the tiles, which fits column sizing.

Purple is room/heart/portal stuff. The bytes don't seem to differ on those, so you'll see that as always purple, as purple was the color I tested with.

Water and lava does not seem to be saved in this file, so you'll see it as empty paths.

All the images were read using a simple java program I made to read the files and output an image based on it.

- Wirlaburla