I thought that was the case for all gifs. Reading a bit on wikipedia, does that then mean that every individual frame can only have 256 different colors, and an actual 8-bit gif only has the same 256 colors for all its frames?
8-bit here represents the possible colors. With 8 bits of binary, no value can exceed 256. In terms of the color, there are 256 possible RGB combinations (8*8*4)