Breeders of colored breeds and in particular the red-factor canary for aesthetic and commercial purposes, usually resort to the coloring feed for canaries, which manages to accentuate the tint of the plumage of their birds.
There are natural foods capable of intensifying the red coloration of feathers such as carrot and tomato, there is also the breeding paste with dye and specific preparations that are sold in shops.
It is not important how much coloring food is given to the canary, but the regularity in the supply, which must be started before the moulting and stop giving it some time after all the feathers have been renewed. It is important to keep the food supply coloring after moulting so that it maintains color.