I just wanted to draw Roman costumes really....

Dave is a senator, hence the purple (if it were coloured) strips on his tunica and toga. Ted is a wealthy merchant citizen, so wears white tunica and toga, but is a little bit vulgar and wears more than one ring, displaying his wealth. These are pretty much the Roman equivalents of their current social positions, Dave is from an old noble family (which is also horrifically inbred, which explains why they're all screwy) while Ted's family is newer money, but very wealthy.