this may sound like a shitpost but in the 19th century green carnations were a sign of being gay AND in ancient rome, yellowish-green clothing was a sign that a man was effeminate and therefore probably gay, so green is a gay color and only gay people can wear it now
C’mon… Even his bottle of wine is gay.
What could be more gay than Grantaire except Grantaire with Enjolras ?
¯_( ಠ_ಠ)_/¯ 