Caveat - I am assuming postulating “background colour” compatible with Flat Black is acceptable on this board. If not I am fine with deleting this post.
As Brett discussed in the dev levels thread, domestic animals, usually called “beasts” as a generic term, are commercial products. To me that means that many, if not most, of them have been run past a marketing department to make them “Stand out from the herd.”
As a pure matter of background colour, there should be interesting beast brands, tweaks, and commercial markings.
For example, beasts designed by the Empire might be deepest black with small white spots to invoke the depths of space. They are usually seen in areas in desperate need of food aid, so are not prestigious at all despite their appearance.
Legacy beasts from the colonial period might bear corporate dress or national symbols from Old Earth long past the demise of the sponsor. “Pepsibeasts” and their associated “milk” have been hanging around some colonies so long that pepsimilk is the ONLY acceptable choice for new generations.
“Chocolate Yumyums” are a luxury pet in the Suite. Half puppy, half kitten, and 100% adorable, not only do kids love them but the beast will spew forth a variety of delicious treats when a parental figure signals it’s RF implant with their comgadget.
A surprisingly common colonial beast is the infamous “Slobberbeast,” sent to many colonies with marginal habitability. They roam far and wide during the day, comsuming all manner of noxious garbage and excreting pellets of toxins, and return to the colony at night, where they drool out filtered water and vomit up biomass compatible with the needs of many terraforming organisms. They are also affectionate, playful and fiercely protective of humans. It is thought that many of the less salubrious colonies would have perished after the loss of Eatth without the help of their loyal Slobberbeasts.