I just looked at my humalog cartridge last night and it looked pink. Does anybody know what this means?882-IMAG1247.jpg (1.2 MB)
Looks like you might have hit a blood vessel when you took a shot and it backed up into the cartridge. I would ditch it and start a new one as the insulin is more than likely compromised. The pink/reddish color is likely from the haemoglobin in the blood.