I want to say the Browns and an iteration of the Steeler's helmets just have like a solid color or stripes.
what would be the point of their existence if they didn't? how else could the collect residuals from advertising ten dollar tennie runners that sell for a hundred bux? and war up jackets and the rest of that retarded sports promo crap, that suckers spend rediculous idiotic amounts of money on?
@themnax makes a good point. NFL teams are sports franchises that need to maximize dollar revenue from their fan base. Having a logo is part of the sports franchise formula because the masses need flags and colors to identify with. @I'minmyunderwear is right that it's the Cleveland Brown's. The only team at this time whose logo is the colors without a design.
The Cleveland Browns technically use the whole orange helmet as the logo. Nevertheless they are the only team without a logo.
All teams are required by NFL rules to have a logo, but an exemption was granted to teams with absolutely no chance of winning a championship
Even if a team had just their name, in a specific font and color, that is considered a logo. So the answer is, "No, they all have a logo"
How would you explain the Bengals and Browns then? They both appear to have no logos on the side of their helmets. Bengals just have black tiger pattern and Browns just have a blank orange helmet with a stripe!