I love Joan Allen. I have no idea what's happened to her career (Death Race???), but I think she's a consistently great actress, adept at both comedy and drama. To prove my point, I present as exhibit A her performance in Pleasantville, in which she runs the gamut of emotions and creates a compelling character out of what could easily have been a mere caricature. Hers was, hands down, one of the best performances of 1998, but AMPAS thought differently and instead nominated: Brenda Blethyn (Little Voice), Kathy Bates (Primary Colors), Judi Dench (Shakespeare In Love), Rachel Griffiths (Hilary and Jackie), and Lynn Redgrave (Gods and Monsters). Dench would go on to win the Oscar and she's the actress I'd swap out for Allen (though I say that having never seen Little Voice and therefore being unfamiliar with Blethyn's performance), but then I've never been a big fan of "make up" Oscars.
Allen's Betty Parker begins the film as a solid caricature of a 1950s TV mom, her character literally a character in an old family sitcom. She's a wholesome presence who would never think a bad thing about anyone, capable of only ever so gently scolding someone for whatever minor misdeed will be the catalyst for that week's important life lesson. She cooks, she cleans, she neither does nor says anything that would allow her to evolve beyond two dimensions.
Slowly, as change begins to sweep across the cozy, innocent town of Pleasantville, so too does a change take place in Betty. As she physically begins to morph from black and white to color, Allen infuses her with more depth - the color spreads through her and she gradually awakens to her humanity, her autonomy, her sense of self. She becomes, essentially, a person with desires and thoughts of her own that complicate the perfect, strictly crafted world of Pleasantville. This leads her to an ending that is ambiguous but not necessarily unhappy.
Allen displays a delicate mixture of emotions as Betty struggles to comprehend and accept what is happening to her. She conveys the confusion and fear of her metamorphosis as well as the excitement about the possibilities these changes may bring, often doing so with little more than a flicker across her face or a slight inflection of her voice. Scene after scene shows her growing more confident with the person that she's becoming and the newfound power that she is asserting.
Of all the characters in the film, Betty's arc is the most profound, touching not only on issues of women's liberation but also on issues of racial inequality. It is primarily through her that the film explores civil rights, the most resonant of its themes, and Allen is more than capable of carrying that burden. Hers is a terrific performance as a character that is absolutely vital to the film's success. No wonder it was so easy to overlook.