NEW YORK — Though sales gains are elusive, Gap Inc. is gaining confidence in its products and will spotlight summer offerings with a marketing campaign called Rock Color.

It’s inspired by the summer of 1969, the year the company was founded, and includes a pop-up store, which is actually a converted school bus from the Sixties that will drive to summer resort spots on a mission to sell T-shirts, hoodies, flip-flops and beach hats.

Gap is the latest in a string of retailers to use the pop-up approach to promote merchandise, but those by retailers such as J.C. Penney, Target and Wal-Mart were all stationary. J. Crew has used the mobile approach on the East End of Long Island delivering summer goods door-to-door on weekends in a 1988 Jeep Grand Wagoneer.

The Gap campaign also involves in-store promotions, windows, print ads, direct-mail and outdoor ads and an online microsite offering customers the chance to win concert tickets. Color is a key component of the campaign.

“The summer of 1969 is part of the visual inspiration and soul for each element of this campaign,” Kyle Andrew, vice president of Gap marketing, said in a statement. “We hope our Rock Color bus tour and summer concerts will evoke the fun and freedom of summer while enabling us to connect with our customers on a personal level.”

In previous interviews, Gap officials have said that its takes a few months before customers catch on to reworked offerings and sales gains start materializing. The new campaign could quicken the process by stimulating traffic.

Gap removed the seats, built display shelves and installed a cash register in the bus. The bus tour starts in Los Angeles on Friday and concludes at the New Jersey shore on June 25. Beaches in New York, including in the Hamptons on Long Island, are on the tour, as well.

Gap also is running a contest for customers in New York, Los Angeles, San Francisco and Chicago to win tickets to concerts. Additionally, one grand-prize winner will receive a trip for two and backstage passes to Gap’s private concert here featuring John Legend.

The campaign was developed by Laird + Partners, Gap’s creative agency.

This story first appeared in the May 1, 2006 issue of WWD. Subscribe Today.