it is not hard to tell the difference between a human run ship and one that is run by others, for humans love color, ships run by humans often have painted walls and images everywhere, for ships that have a 'ships human' it is often best to allow them to decorate their living spaces to avoid agitation from staring at monochrome walls all the time (humans that don't decorate generally enjoy music, writing or other creative acts) -- Anon Guest
Every species has an aesthetic, even the ones who don't have eyes. The Pteropts, for instance, prefer smooth, sound-baffling walls and keep sculptures of incredible intricacy. The Cephaloda, a water-borne species, arrange gardens of rocks, shells and coral surrounding their ocean homes. Humans... love colourful things.
There's a reason why most public spaces - excepting designated graffiti zones - are grey. It is the least offensive colour to multiple species' eyes. Well. Those who have eyes to see with. There is only one species offended by Public Property Grey, and that is, of course, Humans. These Deathworlders, whose life is often interesting in deadly ways, hate bland and inoffensive tones, especially when those tones are everywhere.
Humans are the reason that designated graffiti zones exist. They see a blank expanse of wall and feel obligated to fill it. Words, pictures, a mix of the two. Cartoons, if they can get away with it. There is not an empty wall that a Human will not attempt to improve, somehow. When Humans are forced to cohabit, it is best to use a mediator to assist in co-ordinating the group aesthetic.