The Lifecycle Assessments that we have run on our printing products show that there is a negligible difference between B&W and color printing. The basic reason is that the cartridges themselves have virtually the same construction, so there is little if any difference between them. Color laser printers have an image transfer blanket that is not found in B&W printers, this adds a minimal increase to the environmental footprint, but it is insignificant on a per-page basis. 

Although we have observed some differences between black and color cartridges in a few specific cases, we have not conducted any specific statistical analysis, nor have we generated any evidence to determine that the two are substantially different. Therefore, it is fair to assume that they have very similar impacts.