HOT FLASHES: Will KLOS-FM look pretty in pink? We'll see Nov. 25, when the rock station splashes a fresh coat of pink paint all over its office headquarters on La Cienega Boulevard in honor of the arrival of album-rock faves Pink Floyd, who begin a series of four concerts Nov. 26 at the Sports Arena. The group is expected in town a day early, so don't be surprised if they pop up at a KLOS press conference touting the station's redecoration project. . . . We couldn't help but notice that FM-102 program director Sam Bellamy was having lunch the other day with ex-MTV veejay (and former KLOS mainstay) J.J. Jackson. Could J.J., who's been doing occasional weekend work at KROQ-FM, be thinking about going back--full time--into radio? . . . Local faves Chain Reaction have signed with Island Records. The band was wooed personally by Island chief Chris Blackwell, who may even lend a hand in the studio with the group's first album. . . . And U-2 fans can warm up for the band's Coliseum dates this week by tuning into Joe Benson's "The Seventh Day" show, which will go U-2 crazy at about 5:30 p.m. today. Benson has collected about 35 unreleased U-2 tracks from various B-sides of band singles released in Ireland, Germany and the United States, most of which will be aired this afternoon.