In early episodes of the series whenever they watch home movies and slide shows, the pictures are in perfect color not only are they in color but the quality of the film is incredible (for the time)
I dont think this is a slip up because of two reasons
1)I have seen footage of American bombers over europe in WW2 which was shot in colour so colour film was already around when the Korean war was in progress.
2)The reason why the quality looked so good was that the film shot was new and had not deteriorated over a period of years.
Good Quality home movies?
Have you seen the episode where everyone gets together to see Radar's B&W Grainy and no sound looked cheap and fake.
I mean if your son was in war wouldnt you send the best?
This is in reply to Nathan's comment. The reason why Radar's family used the cheap black-and-white film in the home movie was that they couldn't afford anything better. Radar's mother, aunts, and uncles are only small-town farm people. They couldn't afford to use expensive color film like Henry's family used.
Film footage of Henry Blake's family showed a birthday cake for his daughter that read, "Happy Birthday, Molly." Then in the episode where Henry's going home, he calls his family and talks to his daughter "Janey." Name change?
In response to Nathan's comment about Radar's family not sending the best film they could to their boy. Considering that they would have to drive several miles to see Radar on telly, when he said hello to the camera in one episode shot entirely in black and white, suggesting that they of simple means, perhaps they did sent the best they could?