Seifer's lack of adornment sets him apart from most FF characters. His ears aren't pierced, so he's a truly freakish outsider by FFVIII standards; his hair's short and in a simple, practical style; his necklace is little more than a narrow plate on a chain, close to the skin rather than hanging loose.
...Okay, so if we saw someone dressed like that, they'd stand out as over-dressed; but by FFVIII standards, he's very restrained. The red swords ('Fire Crosses', I like to think of them) on his coat are the only really distinguishing features, a personal 'monogram' of sorts, a kind of reflection of Squall's 'Griever' icon.

I'm certain that PhoenixAsh will use your observations as further conclusive proof of R=U, while Besimudo will explain how they show us that Seifer's really the hero while Squall is the infernal villain of FFVIII