Color separation negatives can be made either in camera or from chromes using TMax films, but the
devil is in the details. Making really large separations using continuous tone film would be quite
expensive in this day and age, even if you could locate a reliable supply of a suitable film. FP4 can
sometimes be used, but TMX or TMY is preferable for separation work. It takes a lot of work to
calibrate everything, esp with a process like color carbon, so if any one variable changes, or you lose a critical film, you're back to scratch.