Stevens wasn't much of a religious guy, but one thing he did believe in was the power of imagination. Why? Because imagination opens up all possible versions of reality. How does it do that? By creating reality in the first place. Are your minds blown? Well, they should be. All right, enough already. We'll stop asking questions and leave you with this nugget of wisdom: "Disillusionment of Ten O'Clock" is about this very dynamic. Folks with imagination are able to create their own interesting realities, while folks without it are, well, not.
The only image in the poem that isn't figurative (meaning the thing is literally there in the world of the poem) is the image of the sailor asleep in his boots, which is meant to show the reality of his imagination.
The purpose of listing different colors, and accessories, is to let the reader know that there are infinite variables in life, and only the imagination can limit the possibilities.