The only person allowed to steal the show from the bride on her wedding day is the flower girl.

Yet too often the flower girl’s dress is an afterthought.

That’s changing, thanks to designer Tanya Roukous, whose Katina Katoo line caters exclusively to the wee bridal set.

Katina Katoo, based in Whitman, Mass., offers sweet and elegant dresses without lots of frills and trimmings. The most common details are a sash at the waist and a cluster of flowers (silk, from Europe) in the back or front.

“Little girls should look like little girls,” Ms. Roukous, 36, said. “The point isn’t to create a miniature version of the bride or the bridesmaids.”

Those who play it conservative opt for a white or off-white dress, paired with a sash that matches the flowers or the bridesmaids’ dresses. But Ms. Roukous, who wore a red Halston dress at her own wedding, much prefers to see girls wear color head to toe. Fashionable flower girls combine colors on both the dress and sash – tropical aquas, oranges, and fuschia are popular at the moment, dovetailing with trends in women’s bridal wear.

Yet the standard seems to be pink. “We sell more pink than white,” Ms. Roukous said, “and pinks in every shade, from peachy, blushy pinks to very vibrant hot pinks.”

Ms. Roukous, who studied at the Fashion Institute of Technology, started out designing bridal wear for grown-ups. But then her bridal clients became mothers and asked her to make christening gowns. Soon she found her niche: special occasion dresses for girls (12 months to 13 years of age – size 16).”Katina Katoo” is the nickname her father gave her as a girl.

She designs with the comfort of a little girl in mind. “They’re not ones to suffer for beauty,” Ms. Roukous said. So she lines everything – and double lines the skirts, to protect against those very scratchy crinolines.

With couples marrying later, and second marriages combining families with young children, the number of girls in wedding parties is growing. For Ms. Roukous, that means coordinating the looks of several girls of different ages, rather than choosing one dress for every girl.

“A 5-year-old wants to look different from her 12-year-old sister,” Ms. Roukous said. Younger girls often wear a dress with a full skirt that falls above the ankle, while older girls go for A-line skirts that fall right on top of the shoe.

Sashes are tied in a half bow (just one loop). “A full bow is just too girly,” Ms. Roukous said.

Dresses, which range in price from $210-$270, are cut to order based on basic measurements that a retailer or parent can take. Orders should be made at least 12 weeks in advance, but not too early – children grow fast.

Dresses can be reworn for other special occasions or portraits, but their versatility isn’t the point. After all, every girl remembers the first time she walked down the aisle – and what she wore.

What’s next? A small line of bat mitzvah dresses.

Katina Katoo dresses are carried by Leeper Kids, Grand Central Terminal, 212-499-9111, www.leeperkids.com. Katina Katoo’s full collection can be seen at www.katinakatoo.com.