She may be follically blond, but as an actor of distinction who's all of 25, Reese Witherspoon reveals interesting dark roots even as she plays golden girls. And while I'm not saying physiognomy is destiny, I do think that sharp, stubborn little Witherspoon chin has something to do with it: No matter how virginal or blithe she's supposed to be (in movies like ''Fear'' or ''Cruel Intentions''), her structural pointiness belies easy sweetness, suggesting the iron girder determination that supports her best performances, in movies like ''Pleasantville'' or, especially, ''Election.'' To see Witherspoon daintily claw her way to success as the infernally perky Tracy Flick, candidate for student council president, in that triumphant antiblond manifesto, is to see a young actress in exciting control of her Clairol powers.
In the likable lollipop comedy Legally Blonde, Witherspoon is flaxen to classic California girl specifications as Elle Woods, a West Coast campus princess who wafts through life on a cloud of privilege. Elle is rich, popular, and outfitted in the kind of predominantly pink clothes only the very fashion victimized or self confident would dare wear. But just when she expects to grab her big prize -- a marriage proposal from her cute boyfriend, Warner (''Tigerland'''s Matthew Davis) -- she's devastated to learn that her mealy beau, who has political ambitions and a place waiting for him at Harvard Law School, has no plans for a ''dumb'' blondie in his future. (His chosen fiancée, Elle soon discovers, is a pedigreed prune with a dank, brunet worldview, and she's wonderfully played by Witherspoon's ''Cruel Intentions'' costar Selma Blair.)
The cheery, simple punchline of ''Legally Blonde'' is that dumbness has nothing to do with it: Don't hate Elle because she's beautiful, and don't dismiss this summer flick because it's not as hip to itself as ''Clueless'' or as well made as ''Election.'' Sweetly intent on proving she's worthy of the lummox, Elle gets herself into Harvard Law School too, bowling the admissions committee over not so much with her transcript (although she does have good test scores) as with her admissions video (directed by ''a Coppola'').
Elle not only makes it through law school, of course. She triumphs, winning friends and influencing people through a combination of glinting highlights, sturdy self confidence, and, it turns out, real brains packaged in silly clothes. I'd be happier for future scholars of hair color everywhere if screenwriters Karen McCullah Lutz and Kirsten Smith (''10 Things I Hate About You'') took more risks and gave Elle more of a contour, making her either sharper or more rounded, or if first time feature director Robert Luketic messed with the unflaggingly light tone some more.
Actually, I'd be happier if I had a little better idea of what really matters to Elle (besides turning lemons into lemonade). And I desperately want to know, even as I laugh and admire her enchanted existence, whether this blond operates from a plan or in a burst proof bubble. But maybe that's something only her hairdresser knows for sure.