Sorry...I realized I answered before I logged in! Here it is again!
- Color--as the society around the characters changes, and they begin to change with it, color is introduced into Pleasantville. Take a good look at how Joan Allen's character (the mom) reacts when she begins to have "color".
- Perfection disappears--the idea that change creates difference is explored thoroughly (the basketball team is proof of this).
- How the characters are presented--Reese Witherspoon's character goes from the "bad girl" to the girl who wants to stay in Pleasantville...whereas Tobey Maguire's character is the guy who initially wants to stay but then leaves.
- Exploration of Sexuality--a bit more mature of a subject, but is absolutely illustrated by Joan Allen's character exploring (also lends to the idea that women do not have to be at a man's beck and call anymore).
- Utopian society good or bad?--huge theme that is focused upon throughout the course of the film.