Continuing on "Empiricism and the Philosophy of Mind" (1956).
We consider a couple of Sellars's "thought experiments." In one, a guy who works in a tie shop thinks he understands "green," but when electric lights are added, what used to be green now looks blue, yet looks green again when he takes it outside. This is supposed to explain how "looks green" is an evolution from "is green," as opposed to the appearance being the foundation for us eventually positing what things are in themselves.
In another near the end of the essay, we consider a whole race of people, "the Ryleans," who lack inner concepts for psychological states. They end up inventing such terms to explain others' behavior: e.g., he says "blue" when he sees that green tie because he's having a blue appearance in the presence of that green thing in weird lighting. And only after they learn how to use these terms to describe other people do they then apply them to their own experiences: Sellars thinks that mental terms like "appearance" that you might think apply to some pre-linguistic "given" are really terms in a theory of human behavior.
But of course it's more complicated than that, and Lawrence "Dusty" Dallman is still with us to help us sort things out.
End song: "Senses on Fire" by Mercury Rev. Check out the interview with singer Jonathan Donahue in Nakedly Examined Music ep. 14.