Residents of Prince George's County have long been irked by the reluctance of Macy's and similar upscale retailers to open stores in the area.

Soon an army of 35 will avenge the snub.

Colours, a performing arts troupe headquartered at Parkdale High School in Riverdale, will take a piece of Prince George's County to Macy's flagship store in Manhattan, where it was recently invited to perform.

"The kids act like ambassadors for the county," Jason Cook, the group's 30-year-old founder and director, says from a purple-walled office lined with pictures, newspaper articles and awards featuring Colours. "When we go away to perform, the kids are treated like royalty."

The group's appearances have garnered praise from audiences throughout the region. One student in Newport, Pa., was so impressed she sent the group an e-mail after a February show at her middle school.

"It was unlike any performance I had ever seen," the student gushed. "It was nice to have an assembly that wasn't boring."

Maryland education officials also were impressed when the troupe performed this year at a celebration honoring Maryland's best schools.

"They were a tremendous hit," recalls Darla Strouse, director of corporate partnerships and development for the Maryland State Department of Education. "We always hear about talent in New York and Hollywood, but we have talented students right here in Maryland."

Hometown audiences can catch the ensemble this week, when it performs the musical "Grease" at the Prince George's Publick Playhouse in Cheverly.

Cook gets a kick out of the audience's reaction to the production's mostly African American cast.

"We like doing 'Grease' because it's typically associated with an all-white cast," he says of the musical, whose characters are '50s-era high school students. "But we started having a multicultural cast way before Broadway did."

Cook grew up in Miami, where he was active in children's theater; when he moved to Prince George's to attend college, he was surprised by its lack of performing arts venues for children. After graduating from the University of Maryland at College Park in 1992, he began teaching at Charles Carroll Middle School in New Carrollton. There, he and another teacher, Douglas Anthony, decided to start a program that would allow Prince George's students to explore the arts.

The Charles Carroll students chose the name Colours to represent the group's spectrum of races and religions.

Since then, the program has become so popular that Cook has been invited to introduce it to three other county schools: Parkdale High School, where he is now a drama teacher and where the traveling troupe is based, and Arrowhead and Templeton elementary schools. There also are plans to expand the Colours Arts in Education program to three more Prince George's schools.

Top-notch talent was recruited to direct the Colours spinoffs at various schools. Keitha Shepherd, for example, is the group's vocal instructor at Templeton Elementary.

Shepherd is a member of the popular Washington-based singing group Pure Soul, whose hit single "We Must Be in Love" topped R&B charts in 1995. Now a music teacher at Templeton, Shepherd says she's impressed by Cook's dedication to the program.

"He's a hard worker," she says. "He's a perfectionist, so you have to have a certain mind-set to be a part of this. You can't just come in there and work with the children for a few hours. You have to really be into it."

Cook, for his part, shrugs off the long hours he spends at the school, since he doesn't have a family. (He also coaches volleyball and softball.)

"I equate it to if I were a doctor or lawyer," Cook says. "Being a teacher is no different. You're a teacher 24 hours a day. . . . I'd much rather be sitting here than in a meeting with a bunch of adults."

Cook demands the same level of intensity from students. He stays in touch with teachers and principals to make sure Colours performers keep up with their schoolwork.

Jessica Dukes knows all too well how tough Cook can be. The director pulled the former Parkdale High School student out of Colours when her grades began to slip.

Colours "made me a better person," says Dukes, now an 18-year-old college sophomore studying mass communication and theater at Frostburg State University.

"When I got pulled out of Colours, it helped me get better grades. It helped me get into college."

Dukes returned to Colours this summer to direct the performance of "Grease." She says the troupe is the same haven for artistic spirits it was when she joined six years ago.

"It's a place where you can go to let your inner characters run wild," Dukes says, raising her hands with a dramatic flourish.

"We get to show our true talents," agrees Christopher Law, a 15-year-old Parkdale sophomore whose dark brown hair is braided into cornrows. "We don't have to front for anyone here."

Law is playing Danny Zuko in the troupe's upcoming production of "Grease." He admits that the hours spent rehearsing limit other things he likes to do, such as playing basketball and hanging out with friends. But he says being on stage more than makes up for it.

"It's worth it," he says.

Colours performs "Grease" at 10 a.m., noon and 8 p.m. Wednesday, Thursday and Friday at Prince George's Publick Playhouse, 5445 Landover Rd., Cheverly. Admission to evening performances is $6 adults, $4 students; daytime performances $3. Call the Publick Playhouse at 301-277-1710 or Colours at 301-486-3729.

CAPTION: Regina Ehrmann, in white blouse, as Sandy, rehearses with fellow members of the Colours performing arts troupe for the group's performance of the musical "Grease."

CAPTION: Christopher Law, as Danny, performs a song and dance number with other cast members.