COL Palette File Format

256-color RGB palette format.

Each file maps color indices (0–255) to RGB values. Models reference palette entries via color_index in solid-color face data (see 3D.md).

Overall Structure

Populated COL files are exactly 776 bytes. fxart/CLDTEST.COL is an empty placeholder, not a valid palette.

Palette entry N is at offset 8 + N × 3, yielding bytes (R, G, B).

Usage

COL files are per-scene, not per-model. Different levels use different palettes (e.g. ISLAND.COL, CATACOMB.COL). The same color_index in a model’s face data produces different colors depending on which palette is active.

Entry zero can be nonblack. The world palette upload forces its displayed RGB to black.

Glide world palette conversion

The world loader converts each channel of a populated COL file to six bits by shifting it right two bits. The world palette upload shifts these values left two bits to form the RGB texture table and forces entry zero to black. Thus an unmodified world palette channel is 4 * floor(channel / 4), with a maximum of 252. Texture filtering operates on these uploaded colors, before lighting and framebuffer conversion.

This conversion belongs to the world palette loading and upload path. The renderer also has direct RGB palette uploads, which preserve their input bytes; it is not a conversion inherent to the COL file format or to every texture. Decoders and generic exports retain the original eight-bit file values.

Related Formats

• TEXBSI — the CMAP subrecord in animated TEXBSI images uses the identical 256 × RGB triplet layout (768 bytes). CMAP palettes are embedded per-image; COL palettes are per-scene.
• FNT — font files embed their own BPAL/FPAL palettes (same 768-byte layout), independent of scene COL palettes.

External References

• UESP: Mod:Palette Files — dedicated Redguard COL page with the 8-byte header + 768-byte palette layout.
• UESP: User:Daveh/Redguard File Formats — COL size and palette usage notes.