A drug delivery device with differentiating features is provided. The drug delivery device comprises a dose setting mechanism (102, 500), a cartridge holder (104, 300), and a cartridge (120, 400) contained within the cartridge holder. The cartridge holder is secured to the dose setting mechanism and comprises a collar or ring (310). The ring has the same color as other differentiation features on either the dose setting mechanism or the cartridge, or both. The color-coded ring is configured on the cartridge holder such that when the cartridge holder is assembled with the dose setting mechanism, the color-coded ring remains visible.
