Developing natural colorants can take work. A pet food ingredient supplier needed to breed their own plants when they needed a particular color.

Most humans’ perceptions of kibble color don’t match the actual pets’ ability to see color, much less the animals’ reaction to that color. Ultimately, pet food colorants influence people more than dogs or cats, and as such colorants play a role in positioning a pet food product. Natural pet foods need natural colorants, and when those colors aren’t available, farmers may be able to breed a plant that can provide just the right natural red. Read more.
Wall, Tim. “Sweet Potato Bred for Natural Pet Food Colorant.” PetfoodIndustrycom RSS, PetfoodIndustry.com, 7 Apr. 2021, http://www.petfoodindustry.com/articles/10170-sweet-potato-bred-for-natural-pet-food-colorant.