THE COMMENTATORS' NEW CLOTHES.

Byline: Barbara De Witt Fashion Editor

They diss and dish, ooh and ahh.

No fashion trash or triumph goes unnoticed by this couture-wearing corps of TV commentators.

While they stand alongside Oscar's red carpet at the Academy Awards, they're busy reporting live on what movie stars are wearing, but their ensembles are just as vulnerable to public scrutiny.

Talk about a case of ``eyes wide shut.''

Take Joan Rivers and her little sidekick, daughter Melissa, who host E! Entertainment Television's pre-Oscar show. They've got almost as many designers wooing them as do the stars, and they've got the big bucks to buy what they want if nobody offers it to them. Yet they don't always look as polished as possible. Some years Joan is too flashy and Melissa looks like she's reporting live from a Silver Lake night club rather than the Academy Awards.

Both women admit to their mistakes. According to Joan, she once wore a gown she describes as ``a navy column with major shocking pink ruffles'' that made her look foolish on television. ``I looked like a toilet paper holder,'' she confessed to the Daily News.

Melissa says she once wore a brown plaid chiffon three-quarter length strappy column during a heat wave that she feared was too casual for the event. And it was.

They didn't say who designed their fashion disasters, but evening gown designer Heidi Weisel has dressed them for previous occasions. According to Weisel, ``They were always nice to me in the past and I'd love to work with them again.''

But Joan, who wore a red sequined gown by Pamela Dennis last year, is reportedly going with a Vera Wang number in eggplant with a tulle or net cage over it. And Melissa, who wore Vera Wang last year, hasn't decided.

Meanwhile, other TV commentators are scurrying around town looking at all the designer collections being presented this month in Beverly Hills boutiques and hotels.

At the Escada open house at the Peninsula Hotel, local NBC anchor and Oscar commentator Laura Diaz was hot for a seafoam green gown with jeweled straps, but couldn't bring herself to commit that day.

``I want something that will photograph well yet be fashion-forward ... but not too exposed. And that's tough to do this time of year.''

Mary Hart of ``Entertainment Tonight'' has made a selection from the Escada collection, but sources at the Amsale design house say Hart has also chosen one of their gowns. According to Hart, Amsale's ice blue ball gown topped with embroidered and beaded lace is ``a stunner.''

Her co-host Julie Moran is still gown shopping but has her sights on a two-piece gown with a black marcasite crystal halter top by the young and hip designer Douglas Hannant.

``Access Hollywood'' glamour girl Nancy O'Dell isn't bothering to shop. According to her stylist, Nicole Allowitz, she's sticking with her favorite designer, Mark Zunino, who's creating something so awesome we'll have to wait until Sunday to see it.

Although there's a trend this spring toward gowns with plunging necklines, New York Post gossip columnist Cindy Adams is wearing a black velour kimono top with black pants when she dishes for E!, says her designer Joanna Mastroianni, who held court earlier this week at L'Ermitage Hotel.

But People Magazine's West Coast style editor Steven Cojocaru may take the plunge and expose his chest. The flamboyant fashion independent, a frequent guest on a number of networks, has a reputation for wearing his shirts unbuttoned and topped with outrageous red, pink and orange fur coats.

Earlier this week, the clotheshorse was still contemplating his choices. All he'd say was, ``It'll definitely be something fun.''