Martin,
At Woodland Hills, where Hepburn and HH enjoy 9 holes of golf, it's a Billy Bell Sr. course. The bunkers you see in the film are the ones recently redone by Geoff Shackelford, in-house with the superintendent. However Geoff was not responsible for the colorization effect used in the movie! I can assure you the course is in fact normal verde color!
In the movie, DeCaprio/Hughes is seen and heard telling Odie, is assistant that he was going to try to make the Wilshire Country Club. As noted in the above post, that in fact was wrong. In the real life scenario, Hughes was aiming for The LACC (I would suppose #5 considering the length as well as his flight path where he ended up crashing) and they actually used a shot of him pointed at The LACC in the movie. I have the clipping around here somewhere, but I can't post it right now but I think he hit about 3 or 4 houses, as well as killed one civilian on the ground, and it's a miracle that he didn't kill more. From what I've got from the LA Times archives, it's pretty accurately portrayed in the movie with the exception to the quote of where he was trying to land the plane.
At Wilshire CC, the scene where he is landing his plane is taken on the fairway of the 6th hole, which then the plane was then moved over to the 8th for the shot of the actual house which overlooks the 8th green/9th tee.
The story that Adam Clayman and myself were told about Hughes and his house at Wilshire was that he coaxed Ava Gardner to look out for him and his golf partners when they got to the 8th green/9th tee-- come out on the balcony, dressed in a pretty much see-thru neglige' of sorts. This would allow him to take advantage of a press on the 9th!