At one point, when Jennifer tries to use a bathroom there aren't any toilets. This is a clever reference to an FCC ruling during the 1950's, which stated that toilets (or any reference to their use, such as the sound of flushing) could not be presented on television. While this continued on broadcast television well in to the late seventies, the barrier in movies fell in 1960 (two years after the Pleasantville scenario) when Alfred Hitchcock persuaded the film censors to allow the flushing of a toilet in Psycho (1960) because it was integral to the iconic shower scene.
Since every scene from the middle of the movie on had to be in some way digitally changed to have black and white characters interact with characters who are in color, technically this film had the most digital effects shots until Star Wars: Episode I - The Phantom Menace (1999).
For the sequence where Bud is applying the gray make-up to his mother, the color of the make-up was actually green. When they had to "black-and-white" the scene, the green tones were utilized in the same way a green screen is, except it created a mask for applying desaturation rather than replacing the area with an image. Conversely, when Betty first visits the soda shop, she is in full gray make-up, which meant that Joan Allen was shot wearing full green make-up, that is subsequently removed by Bill Johnson (Jeff Daniels).
Writer and director Gary Ross acknowledges these cinematographic homages: The scene of J.T. Walsh in front of the bowling alley scorecard recalls Patton's speech in front of the American flag in Patton (1970), and the courtroom segregated into black-and-white characters downstairs and "colored" characters upstairs recalls To Kill a Mockingbird (1962).
The Native American in the test pattern behind Don Knotts changes from having no expression to angry and then sad as the movie progresses.