color negatives are based on the very same silver halide crystals that B&W negatives are. the only difference is that in color negatives there are 3 layers of silver halide crystals suspended in gelatin dyes (Cyan, Magenta, and Yellow).
if your intent is to reclaim the silver, then theoretically color negatives would have more than B&W negatives. how much more would highly depend on how much silver remained after processing (which would also be dependent upon exposure of each frame). i imagine it may be more beneficial to try and reclaim silver from unprocessed rolls of film as all the silver would remain in those rolls of film.
on another note, i am not aware of a reliable process to reclaim silver from physical rolls of film, whether it be processed or unprocessed. the reclamation processes i was familiar with always involved extracting the silver that remained in the used chemistry after development.
furthermore, it was never described to me as a financially beneficial endeavor to reclaim the silver, rather most labs and darkrooms did it for environmental reasons. in a situation where you have a high end lab running massive amounts of film through processing, the value of the reclaimed silver could reach a significant level and thus make it financial worthwhile in some respect.
finally, the reclaimed silver (as i understand it) is still not in a state that would be of interest to most involved with precious metals. i imagine additional chemical treatment would have to take place to get the material on par with true silver prices, but i would defer to a chemists opinion on that matter.
any chem nerds on the forums that could shed some light on the different chemical states of silver and the processes involved in transforming it into something of value?