Party Lines : A BIG NIGHT OUT CAN PRESENT A BIG PROBLEM FOR GUESTS WHO OVERSTEP THE BOUNDS OF ACCEPTED DRESS. ORANGE COUNTY IS MORE RELAXED THAN SOME AREAS, BUT THERE ARE RULES TO AVOID BEING THE OBJECT OF ATTENTION FOR ALL THE WRONG REASONS.

They are the fashion victims of Orange County’s social scene:

There’s the society matron who overdresses for every opening night at the Orange County Performing Arts Center. There’s the woman who attends an opera ball looking like she just left the office. And there are a few female guests who turn up at the Newport Harbor Art Museum’s Black and White Bash every year and impress the crowd not by what they’re wearing, but by what they’re not wearing.

While the dress code for Orange County’s social engagements is more relaxed than in areas such as New York, there are some rules of social dressing worth following lest one end up the object of attention for all the wrong reasons.

Here, when the invitation calls for black-tie attire, a man is safe in a tuxedo and a woman can usually wear a short or long dress. When in doubt, opt for a long gown, says Gayle Anderson, chief of protocol for Orange County.

“I’m personally more comfortable in long--it’s a little safer,” she says. “But in modern times, a woman can wear a short dress. We’re becoming a more casual society.”

At some black-tie events, women can even get away with wearing palazzos.

Never wear work attire to a black-tie function, as one woman did to an Opera Pacific ball.

“She wore a suit. Oh, what a faux pas,” says Anderson, a former opera ball chairwoman. “If you’re going to do that, you’d be better off not to go.”

White-tie events are rare in Orange County--they’re usually reserved for extremely formal weddings and an occasional ball. Still, when the invitation says “white tie,” even in laid-back Southern California men are expected to don a tuxedo with tails and a white tie.

Dark suits are not appropriate for a white-tie event, although they can be worn to some black-tie affairs. Women should wear their fanciest ball gowns to white-tie functions.

“It’s nice to have a really formal event to go to a few times a year. It’s fun to see what you really look like in all that stuff,” says Gael Lauritzen, owner of 341 Bayside in Newport Beach.

Cocktail attire means sport coats or suits for men and short dresses or pantsuits for women, Lauritzen says. The trouble starts when there’s a vague dress code tacked onto the invitation, such as “dressy casual,” “casual elegance” or the nebulous “California chic.” One person’s idea of casual might be blue jeans, while another’s can be a suit or sparkling strapless dress.

Any mention of casual or California signals that clothes should be relaxed, colorful and not too structured, but made of a fine material, such as silk.

“It needs some comfort level, and it needs some glamour. It’s not casual sloppy,” says Billur Wallerich, spokeswoman for South Coast Plaza, Costa Mesa. “That’s when you bring out your silk palazzo pants and tunic. The fabrics are drapey rather than stiff.”

For women, silk pantsuits work well for such occasions. Men can wear a dark suit and leave the ties at home.

Still confused? The invitation, gala theme, season and location of the event offer clues to expected dress.

“When you’re in doubt, wear black,” says Catherine Thyen, chairwoman of this year’s Candlelight Concert to benefit the Orange County Performing Arts Center. “Choose a dress with a simple line and pearls, and you can get away with anything. You’ll be pretty tame-looking among all the peacocks, but at least you won’t be a peacock among swans.”