Lights

Data File: Light.mul
Index File: LightIdx.mul

You can compute the following values from the Extra field in the index file.

Sizes:

short width = (extra & 0xFFFF);
short height = ((extra >> 16) & 0xFFFF);

Data:

sbyte[width * height] additiveLightmap;

For each pixel (loaded top to bottom, left to right), add the lightmap value for each R, G, and B.
As the value ranges from -31 to 31, you could easily apply a hue by using the color entry at Math.Abs( value ).

See Also:
 - Index Files