The Big Bang Theory #4.22
Raj:
Come on, Sheldon, open the door!
Sheldon:
I don't want to hug you.
Raj:
I don't want to hug you either, I was just feeling blue.
Sheldon:
Blue. As in depressed.
Raj:
Well, not so much depressed as 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 colour to lonely.
Raj:
Nothing rhymes with orange; it's probably lonely.
Sheldon:
Alright. Come in, you look positively orange with loneliness.