Early on in a promo pic, Fujiryuu drew him as blonde. I'm not sure if there are any other blonde images at all; thereafer, he was always the grey/purple haired version we know. Ozaki didn't even have stubble back then, or in those early chapters.

While we're laughing at Fujiryuu's art, I will probably never convince my brain that Ozaki is going up the stairs here rather than doing some bizarre hopping dance. Seishin's look is one of realizing that his dear friend has gone mad. Again. It's an appropriate look for when he just starts skip-dancing around like a damned nut.

And here's a quick omae shot with his self insert. The barber of Sotoba?!