Colors...

In response to Katie's posting on colors:  Red definitely says wealth.  It also signifies eros in some poetic contexts, perhaps why Fortunata wears red.  Red and purple make a  come-back in 38, when Hermeros declares that the cushions in Trimalchio's house are stuffed with purple and crimson stuffing.

I have always wondered (without actually researching it) if the red and green so prominently on display in the Cena have something to do with the Circus factions-- see this entry on circus factions for more.  This would fit in with the imagery of spectacle, gladiatorial games, theatre and mime that is ubiquitous in the Cena. 

The illustration depicts a member of the Green faction and is part of the Quattro Aurighe mosaics in the Museo Nazionale Romano (Rome)