Colour map

Support for PNG colour maps were added to Worms Armageddon with the v3.6.19.7 Beta Update (released on 9 February 2004). W:A only accepts maps that are 1920×696 in size, and use a palleted 256-colour mode. The number of maximal colours that may appear in the map is restricted as well. W:A stores the extra map settings (water level, borders, etc.) in an extra PNG chunk.

Colour limitation

Since W:A uses a palleted display, the number of colours that may appear simultaneously on-screen is limited. The majority of the colour space is used for in-game graphics for the Worms, weapons, objects, water, UI elements, etc. Therefore, the colour maps may only use a limited number of colours in the palette (not counting black, which is treated as transparent), without affecting other Worms graphics:

• 64 colours and less - the map will be displayed perfectly, with no glitches;
• 65-96 colours - the map background sprites (falling debris, clouds, etc.) are removed;
• 97-112 colours - the entire background becomes solid black;
• 113 colours and more - the map will not load.

PNG chunk

W:A stores the extra settings in an extra PNG chunk, labeled w2lv or waLV. The chunk, excluding the label header, is 40 bytes long, and seems to contain the same data as the header for monochrome maps.

TweakPNG allows manipulation of PNG images on the chunk level, thus allowing chunk import/export, etc.