F4U-1A (BuNo 17652) Ens. Frederick J. ‘Big Jim’ Streig, November 1943.
In other cases (like Strieg’s White 3 appears to be), a uniform blue color was used that was lighter than non-specular Sea Blue but darker than Intermediate Blue which, upon careful inspection of the available color photos, appears to possibly be Azure Blue (unlikely for forward bases with limited paint stocks) or a 50/50 mix of the top two camo colors which any squadron would likely have on hand, thus creating a color that is visible when overpainted on both colors.
As for some pilot’s recalling the red surrounds always being on their aircraft, you have to remember that they flew these aircraft for a few months (which did indeed start out with red outlines), but then had fifty years of being saturated with paintings, model kits, and warbirds all depicting red surrounds. I have lost track of how many pilots I have interviewed over my career illustrating military history books (well over 120 books) that told me “I was there so I know what it looked like” only to have photo evidence clearly refute their memories. This is in no way faulting those incredible men. Human memory is faulty in the best of circumstances, ask any police officer what it is like to interview witnesses to an accident or other event that just transpired, they will tell you that they will get as many different stories as their are witnesses. Expecting these guys to recall details of their aircraft (and the dates applicable) flawlessly more than half a century later is simply unrealistic.