Those aircraft weren't in the Philippines nor was it 1941 though the photo may have been released in '41. "US Army Air Corps Curtiss P-36C Hawk fighters of the 27th Pursuit Squadron (27PS), 1st Pursuit Group (1PG), in flight in step-down formation against clouds; aircraft are seen painted in a temporary "wargames" camouflage scheme, with each aircraft carrying a different design. This temporary water-based paint scheme was painted solely for display at the 1939 National Air Races, Cleveland, Ohio, and was never used in any wargames or maneuvers "
If I'm not mistaken, that looks like one of the Hawk 75s used in the german progaganda film "Kampfgeschwader Lützow". The G+F code is unusual for Luftwaffe aircraft, however, one of the Hawk 75s which were painted with RAF markings had that exact code around the RAF roundel: G (roundel) F
It is very likely. The side LW cross seems to be applied on overpainted roundel. What is more it seems that there is the overpainted fin flash on the fin.
Edit.. GG, bingo ! The Hawk with the G-F code is the middle plane seen there...
Also not sure about the grey colour there just because of the "K" letter. The grey colour would be much lighter on the silver background IMHO. The red one ( especially the dull red ) is more contrastive while applied on the silver surface. The pics were taken ( like the entire movie as well ) with filters ( the yellow one I would say ) what can be noticed while looking at the fin flash. The red is light but the blue is dark. As a result the G-K plane could have had the "K" letter of the red and the "G" one of the black for instance. Contrary to that, it seems the G-F kite has the code letters of the same colour. The Snautzer01's shot and the screenshot from the movie confiem that rather. Both letters are light and almost of the same tone the "K" letter is. However the red colour sounds a little bit strange if we talk about the LW. This might result in using of the another paint that was more "popular" for the LW planes in that time , the RLM02 for instance.