The styles are defined with an image file,
lixrecol.I.png.

The first row matches the colors of the spritesheet, lix.I.png. These colors are chosen to be easily differentiable when working on the sprites.
The styles inside the game are each defined by one row in addition to the first. For each style, it is created by exchanging in the spritesheet each color of the first row by the color directly under it from the style's row. Bright pink (255, 0, 255) is transparent in C++ Lix. D Lix also supports alpha transparency.
1st row are the key colors from
lix.I.png.
2nd row is the regular singleplayer color, Garden.
3rd row is the highlighting color for lix under the cursor.
4th row is the color for potential neutrals.
5th row is the first multiplayer color, Red.
C++ Lix runs with 16-bit colors (D Lix runs with 32-bit), but lixrecol.I.png has 24-bit colors. Thus, some similar colors might become equal inside the game, perhaps shirt and pants of some multiplayer styles.
-- Simon