Are those the same as or the same width as the 16' GT wheels? If so, you can do a 225 without too much issue. I know you said you were more concerned w/looks than performance. That being said, I still have to say this:
That wide of a tire will affect performance in most situations. A regular driving tire of needed sidewall height to maintain proper circumference on that 16in wheel will result in a bit more flex in the sidewall (might be a bit more comfortable but not better handling), the wheels will also chase grooves and longitudinal bumps. In some cases, it can really yank the wheel pretty good. This happens when you run a tire a bit too wide for the rim, and wider tires in general. You may also have some uneven wear and under high performance situations, the tire may roll over a bit or overheat quicker resulting in shorter life. Oh, and they'll weigh more which brings it's own well-known negatives.
Some of those things are very minute, especially if you're not into hauling (removed) around. Still, I was compelled to expel them from my mouth.