Raj: I was just feeling blue.

Sheldon: Blue, as in depressed.

Raj: Well, not so much depressed; just lonely.

Sheldon: I don’t know what color lonely is.

Raj: What?

Sheldon: Red is angry; yellow is frightened; green is jealous; and blue is depressed. Perhaps, we can assign a color to lonely.

Raj: Nothing rhymes with orange; it’s probably lonely.

Sheldon: Alright. Come in. You look positively orange with loneliness.