Section 4: Palette (Terence Fergusson & myst6re)
The following is an overview of the palette data.
Section 4 Format
|0x00||4 bytes||Length (Repeat of previous length header)|
|0x04||2 bytes||Unknown (often blank)|
|0x08||2 bytes||Number of colors in palette|
|0x0A||2 bytes||Number of palettes|
|0x0C||(Number of palettes) * (Number of colors in palette) * 2||Palette data|
After the first length indicator comes another integer, also indicating length. Useless, but it's there. Then there's one more integer; unknown purpose. Then two bytes; unknown (blank often). Then two bytes again; unknown (always 480). Then two bytes; number of colors in the palette (always 256). Then two bytes; number of palettes. Then the actual palette data.
Each palette entry is a 16-bit color. This is unusual - normally palettes store as high quality data as possible, usually 24/32 bit. However since FF7 only ever runs in 16 bit I guess there isn't much point storing any other kind of data. Actually, the data is 15-bit (1 mask bit, 5-bit Blue, 5-bit Green and 5-bit Red).
Palettes generally contain a number of colors that's a multiple of 256. This is because the palette is split up into 256-color 'pages' internally. So the first color is page 0/color 0. Color 256 is page 1/color 0. Color 628 is page 2/color 116. You'll see why in the background section.