I think more to the point, if 0 doesn't represent 0.0, and 255 doesn't represent 1.0, congratulations you've just lost your additive and multiplicative identities and most of the math used in colors falls apart.
The argument for 0-256 feels compelling when thinking about the physical display, but it seems like a very poor fit for any digital image processing or rendering.
The argument for 0-256 feels compelling when thinking about the physical display, but it seems like a very poor fit for any digital image processing or rendering.