...green is jealous
and blue is DEPRESSED.
The Big Bang Theory Season 4, Episode 22
He's DEPRESSED because he's pathetic
and creepy and can't get girls.
The Big Bang Theory Season 2, Episode 12
...because I'm fun,
I'm not clinically DEPRESSED at all.
The Big Bang Theory Season 6, Episode 5
Honestly, I get so DEPRESSED,
there are entire weeks
The Big Bang Theory Season 7, Episode 19
Blue, as in DEPRESSED.
The Big Bang Theory Season 4, Episode 22