Because this is what's confusing me right now. Not so much the palette data, but the image data. I may have just figured it out. Image data is a 4 bit per pixel index into the 2 byte per pixel palette. Wow. That took me longer to derive than it should have. I'll try that out.a 256 color palettes occupies 512 bytes. 4 bits for R, G, and B and 4 unused bits per color.