The more recent Canon cartridges, BCI-3e and BCI-6 colours are so close that people cannot tell them apart. Ironically the cartridges are physically identical except for the BCI-3e black which is slightly larger. The BCI-3e black takes pigmented ink while the BCI-6 takes dye based. Be careful here. Some of the newest Canon printers take both BCI-3e and BCI-6 black cartridges.