It's not an insult. It's a descriptive simile.The irony of someone who uses the screenname mandrill hurling an insult by calling someone an orange monkey. You can't make this shit up.
Do you think the real life Kirk Douglas - the same heroic dude who portrayed Spartacus and starred in Paths of Glory - would hang out on a pooner board exchanging insults with a dude who named himself after a type of baboon?! ...
Nah, me neither.