Peg Sheldrick titles her first full-length play, currently at the New Playwrights' Theatre, "Something Blue." But she could have called it "Something Borrowed." What she's written is little more than a latter-day retread of "Vanities."

A big 1970s off-Broadway hit, "Vanities" told the story of three Texas teen-agers and how they grew up (and apart). Showing them at three exuberant gatherings over an 11-year period, author Jack Heifner slyly let us intuit what had happened in the interim. "Something Blue" has a few more supplementary scenes in the course of its eight-year time span. But essentially it's following the same format -- bringing together its three characters, initially midwestern girlfriends just out of high school, on the day each is to get married. From their passing remarks and the changes in temperament, we glean what's been going on during the intervening years.

But the characters in "Something Blue," somewhat ill-defined to begin with, never evolve in a persuasive fashion or acquire the weight of the experiences they're supposed to be having. On the evidence presented, it's hard to believe they're best friends, harder to believe the rifts that separate them and hardest of all to believe their ultimate reconciliation over hot chocolate and cookies. Wedding day or not, we don't really seem to be touching down at revelatory moments.

Sheldrick has provided each woman with a capsule biography, if not a life. Beth (Carolyn Swift), the first to make it to the altar, sacrifices her artistic ambitions to marriage, comes to terms with the death of her mother and finally blossoms with her own art exhibition. Mary (Mary R. Woods) settles for being a teacher, hitches up with a philandering musician, divorces him, then pursues her heart's desire: law studies. Overly dramatic Flo (Connie Geis) goes the route of the frustrated career woman, hits the bottle, dries out and, at the play's end, is preparing to wed a kook in her parents' rec room.

In each of the three acts, however, the wedding preparations are the chief order of business. The girls fuss with shoes, offstage relatives and ill-fitting hairpieces; they sip mimosas and fret about a missing groom. "Something Blue" never gets under this temporary chaos to more enduring truths.

All three cast members, directed by Ronald Ross, are trying for bang-up performances, but the dialogue does not support their intensity, and they end up looking mannered and actressy. Woods, relying a lot on her own graciousness, comes closest to achieving a believable characterization. Swift is often shrill and forced, while Geis seems to be auditioning for the part of Auntie Mame.

Neither the set, a bleached wooden box, nor the costumes takes much account of time passing or fads changing. But that is a failing of the play, as well. If the characters didn't tell us the years were rolling by, we'd be hard pressed to know it.

Something Blue, by Peg Sheldrick. Directed by Ronald Ross; set, Gary C. Eckhart; lighting, Steve Summers; costumes, Jane Schloss Phelan. With Connie Geis, Carolyn Swift, Mary R. Woods. At New Playwrights' Theatre through June 1.