Parallel - Green Hair

First, Shake-Speare:

Pandarus:  [Hector laughed at] the white hair that Helen spied on Troilus' chin.
Cressida:  And't had been a green hair I should have laughed too.

Troilus And Cressida 1.2.152-4

Then Bacon:     "Aristotle giveth the cause, vainly, why the feathers of birds are of more lively colours than the hair of beasts; for no beast hath any fine azure, or carnation, or green hair. He saith it is because birds are more in the beams of the sun than beasts; but that is manifestly untrue;"

Comment: The Arden editor notes on green: "A color normally associated (as now) with inexperience". But Shake-Speare was erudite, and it has been rightly said that, in seeking an explanation of a difficult Shake-Speare line, one is wise to look first to classical sources. So when one finds a specific reference to green hair in Aristotle (De Coloribus 6), it is fairly safe bet that it was that which prompted Shake-Speare to color Troilus' white hair. But in choosing green rather than azure or carnation, he may have been influenced by Troilus' inexperience.