I can imagine the confusion these American-built aircraft would have caused amongst American AA gunners at Pearl Harbor! By the time they could figure it out, the F3's would have released on their targets and would be racing away to re-gain the Akagi...
The way American gunners were distinguishing targets at Pearl by the time of the second wave, I don't think it would have made much of a difference. At least one P-36 and as many as five SBD Dauntlesses were shot down by US gunners on December 7th. Even the
USS Thresher was attacked multiple times just trying to get back into the harbor over the next two days. Given the anxiety at Pearl and throughout the entire West Coast (see
Battle of Los Angeles), anything with a "meatball" was going to catch a lot of flak, regardless of type. In fact, the pilot credited with shooting down the first Japanese plane of the war in an air-to-air engagement, 2nd Lt. John L. Dains, was killed on December 7th by American AA fire. They weren't being too discerning after the first attacks.
Cheers,
Logan