Bethany Bray had it all over Amy Carter. The recent Herndon High School graduate roller-skated the full length of the East Room of the White House yesterday, clearly a NO-NO for Amy and her pals.

Actually Bethany was one of several scout models using a runway to show versions of the new bright green mix-and-match cadette and senior Girl Scout uniforms to Rosalynn Carter, honorary president to the Girl Scouts, and about 250 presidents of Girl Scout councils.

Jane Freeman, president of Girl Scouts of the U.S.A. and wife of Orville Freeman, a former secretary of Agriculture, explained the new uniforms, proficiency badges, including ones for computer science and aeronautics, the new handbook and announced the Girl Scout gold and silver awards.

Carter, who was once a den mother when her sons were cub scouts, said she was never a girl scout . . . "They didn't have a troop in The Plains or Americus when I was growing up." She was presented the new controversial Girl Scout pin with three profiles, which was considered as a replacement for the traditional pin, but is now being offered as an alternative. "Both pins and valid," said Patricia Cherry, from New Jersey. "I approve of the symbolism as a women's organization, contemporary, pluralistic with a diversity of girls. But I grew up with the old and I have a strong feeling about that too."

While the Boy Scouts had Oscar de la Renta design their uniforms, and the adults Girl Scouts have a Halston label, the new uniforms were developed from focus meetings with the young women to decide the costume changes they needed to fit their activities. The result . . . a five-piece set including jeans-cut pants, skirt, vest and insignia sash in brushed polyester and cotton with a plaid blouse, all of which can be worn as part of a normal school outfit. The pattern and fabric will be available for those who want to make their own.

Many of the adult scouts at yesterday's reception were wearing their new uniforms, which one described as "Halston green," a sage green used for jacket, vest, skirt or pants worn with an off-white blouse. ("I love it," said Jean Anderson, president of the Adirondack Girl Scout Council, who was wearing hers for the first time. "I think it is classy.")

After the receiving line to meet Rosalynn Carter, the women went into the State Dining Room for punch. Ever loyal, many passed up the miniature French pastries for the silver platter of Girl Scout cookies.