The Warg and Warg Rider Appreciation Thread

[Formendacil]

Originally Posted by I, in another thread,

Upon trying out his first set of swords from Gondolin, Legolas finds himself between an ork horde on one side and a Warg horde on the other. (A little known fact is that swords from Gondolin glow green in the presence of Wargs.)

Although posted in jest, I seem to recall an obscure reference in the library at Minas Tirith (where, as I am welcome at Aragorn's Court, I have been found often of late), to the fact that Sting, Glamdring, and Orcrist shone green in the presence of Wargs.

Can anyone with Gondolinic knowledge verify this? If so, was it true for all Wargs, or just those corrupted by Morgoth?