FASHION THURSDAY: STAYING WAY COOL.

Byline: Barbara De Witt Daily News Fashion Editor

Someone, somewhere may be wearing a wool suit, but not you.

It's summertime, and you're hula-happy, going on a surfin' safari, headed for Maui-wowie styles or at least dreamin' about a weekend in Santa Barbara in clothes that don't have to go to the dry cleaners.

No-sweat cotton is the annual summertime fabric of choice, although you'll still find some trendies showing no visible panty lines in spandex capri pants and tube skirts. Or maybe an easy-to-pack, hand-washable rayon or Tencel sleeveless slip dress by the likes of David Dart or Ghost.

But you get the picture. It's a lazy, hazy summer that's big on tropical brights and prints, whether it's a sarong, sun dress, clam diggers with tank top, or a two-piece swimsuit with little boy bottoms. Or merely a silk butterfly (they're at Nordstrom) or flower (Saks has them) pinned on a linen lapel.

Sure, there's an alternative. It's the '50s, circa James Dean and Sophia Loren, and everything they wore - from his white tee and dark denim jeans to her capri pants and halter dresses with oversized sunglasses and high-heeled sandals - are now hot looks for warm days.

Denim is back in a big way (even those classic jeans jackets worn with cotton tank dresses) because of Levi's 125th anniversary. It's also the 20th anniversary of Calvin Klein jeans, so in honor of those early days in deep indigo (before we'd ever heard of stone-washed), numerous jeans manufacturers (Levi's, Calvin Klein and Jordache) are offering the original denim color and style, worn extra long and casually cuffed. And cutting-edge designers such as Max Azria of BCBG are going for total nostalgia with extra snug (lots of spandex) jeans cropped to capri length that will remind you of what the fast girls wore in ``Grease.''

Besides something tropical and a pair of jeans, you'll want an oversized white cotton shirt to update your wardrobe. The man-tailored type, worn like a jacket, makes a perfect cover-up for those skimpy little tank tops. Just pull the collar up, roll the sleeves back and add a neckerchief.

Thanks to the creation of casual Fridays, khaki is still with us in classic pleated trousers and the newer flat front styles. And its headquarters is the Gap, where you'll also find white shirts and black cotton knit tank tops that look a lot like grandpa's undershirts, with straps wide enough to hide bra straps.

At department stores, you'll find fresh variations on khaki, including Op's cargo-pocketed walking shorts. Note that those pockets, which add 10 pounds (20 if you actually put something in them), are tres chic for men and women this summer. If you're not worried about your weight, also consider 26 Redsugar's hip-riding khaki pants in a cotton/lycra blend.

Accessories? Back from the '80s is the cardigan sweater, but don't actually wear it. It's just a prop, to be tied around your shoulders or waist and add color to your ensemble. You'll even see them in black, worn over sleeveless black sheaths.

Other must-haves include some shoulder-grazing earrings; an oversized cocktail ring (platinum or silver); oversized sunglasses with a black plastic ``necklace'' that lets them dangle around your neck when you're not wearing them; a vintage-looking jeweled barrette or hairpin, a hefty silver watch, and a choker or dog collar-style necklace.

Day, evening purses

After a few seasons of carrying our ladylike handbag, we discovered it only looks good at ladylike places ... like the office, church or tea parties. Or shopping with Mom. And rarely is it roomy enough for sunglasses.

Yep, that Lady Di (Dior) or Kelly (Hermes) bag looks out of place when you're hitting the beach, on vacation or spending the day at the zoo with the kiddos.

What you need is a tote, whether it's woven from leather, vinyl or straw. The design options are myriad (ditto on the colors), but the shape is boxy and utilitarian. It replaces the backpack but carries the same loot: cosmetics, camera, sneakers, sunscreen, shades, a book and a ball cap. The brand names to buy or copy: Kate Spade, Princess Foufou, Anna Sui.

For evenings out on the town, you'll want something really tiny, such as a clutch (sooo '60s), or one of those beaded ``Titanic''-inspired bags with a short chain handle. Or go ultra retro with a small handbag covered in old-fashioned fabric to enhance a sleeveless summer shift or twin set with knee-length pleated skirt.

And on your feet ...

There's plenty of toe exposure this summer, whether it's a strappy sandal, a thong (and its beachy cousin the flip-flop) or a sexy slide (also called a mule) with a tiny spike heel. And, yes, those high-heeled platform sandals from last summer are still in.

Think of them as a way to show off all those weird nail polish colors, your e-nail decals and your new toe ring ... and stock up on Dr. Scholl's new pedicure kits.

The fashion rage started in Paris, with Chanel thongs sporting leather flowers on the toe and $455 price tags, but the look has trickled down to drugstore prices and were also spotted this week on sale at Nordstrom.

Too many bunions to share with the world? Go for a colorful sneaker by everybody from Donna Karan and Tommy Hilfiger to Sketchers and Keds. The latter even has a pointy-toed, high-heeled sneaker-like slide designed by Cynthia Rowley and featured in her L.A. boutique.

To show your fashion edge and keep your back from hurting, invest now in flats. Yep, that '50s staple worn by the poodle-skirt crowd is coming back strong and looks great with a pair of pedal pushers.

Status shades

Sunglasses do sooo much more than shade your eyes from those nasty ultraviolet rays and camera flashes.

It's all about 'tude. Pull on a pair of oversized plastic shades and you, too, can be a movie star like Sophia Loren in the '50s. Or try some sassy cat's eyes and impress the mall rats with your fashion savvy. Or look like you know the club scene (even if you don't) with those new yellow or blue-tinted lenses. Or be square with the style that's linked to Cary Grant.

Sunglasses are sold everywhere, from amusement parks to drugstores to specialty spec shops. And the prices run the gamut from $7.99 to $200. Just make sure that the lenses offer protection from the sun's harmful UV rays.

But if you're going for the total image concept, you'll want a designer label (think of it as '80s retro), and you need to know the key players. So, the European names to drop - or wear prominently on the temple piece of your sunglasses - are Gucci, Chanel and Frederic Fekkai, who recently opened a boutique on Rodeo Drive.

However, American designer Calvin Klein has a suave new design with a bold oval contour plus UVA and UVB protection that's equal to any of those European shades. It's called the Avenger, and will be launched at sunglass and department stores to coincide with Warner Bros.' Aug. 14 release of ``The Avengers.''

And, of course, you'll need different pairs for all your wardrobe changes.

According to Mitchell Simmons, a spokesman for Ray-Bans, this is a dial-a-decade year, with numerous retro designs making a comeback.

The company known for producing the first mass-marketed sunglasses (and a fave with Tom Cruise) has brought back its original styles from the '30s (delicate metal frames and spring hinges); the '50s (cat's eyes and big squares); the '70s (oversized plastic bubble shapes and aviators); and some futuristic wrap styles in gunmetal gray.

When it comes to shape, almost anything goes, but rectangular lenses are the newest trend, says Sunglass Hut spokeswoman Sherry Lay. And the color palette is huge, with a strong interest in blue and yellow, and metallics with shiny car finishes. You'll find them in plastic or metal, or a combination, and often with tinted lenses. The ``fade'' lense is back, too, but no word yet on rhinestones and initials like we saw in the late '70s.

- Barbara De Witt

CAPTION(S):

10 Photos, Box

Photo: (1--Cover--Color) On the cover: Summer ensembles from Tommy Hilfiger's Tommy collection are available at Macy's.

(2--Color) Shade the sun in hefty frames like these by Nine West.

(3--Color) Carry your summer stash in a leather woven tote from Banana Republic.

(4--Color) Strap-happy platform sandals by Keds.

(5--Color) Pretend you're on a tropical isle in Tommy Bahama Hawaiian prints, available at Sy Devore in Sherman Oaks, Nordstrom and Saks Fifth Avenue.

(6--Color) One of summer's hottest looks is the striped tank dress, shown here with a lingerie tank top and plaid bucket hat by American Eagle Outfitters, available at most department stores.

(7--Color) Summer essentials include surf, sun and shorts with cargo pockets by Op at Robinsons-May.

(8--Color) Brights are back on the beach, including these designs at Macy's.

(9--Color) Gap resurrects the dark denim jacket, $58, shown with a matte jersey skirt that will take you through fall.

(10--Color) Calvin Klein has put the original indigo blue back in blue jeans.

Box: Status shades (See Text)