Passwell Factor Red 25g. Factor Red is concentrated powder used to enhance the plumage colour of Red Factor Canaries, Red Siskins, Flamingoes and other species of birds that require dietary canthaxanthin to maintain feather colour. Key Features: Contains a minimum 10% Canthaxanthin in concentrated powder form. More cost-effective than pre-diluted liquid preparations. Can be added to drinking water, in soft food or pelleted diets.