March 15, 1991 | The best way to appreciate True Colors is to pretend it's really some divertingly trashy best-seller, the sort of high-gloss potboiler you don't mind staining with suntan-oil fingerprints during summertime reading on the beach.

Otherwise, you might start thinking seriously about the movie's nasty undercurrents of class snobbery. And then you might want to start yelling rude things at the screen.

True Colors obviously means to be some kind of critical backward glance at the stressed-for-success value system of the 1980s. After a brief, not terribly coherent prologue, it begins in 1983, at the University of Virginia law school, where two initially antagonistic students begin a lifelong friendship. Tim (James Spader) is a well-born, smoothly ingratiating fellow, dedicated to a socially-enlightened ideal of justice for all. Peter (John Cusack) is the tightly-wound product of a broken blue-collar home, driven to get ahead at any price.

Time passes. Peter drops out of law school to take a job as assistant to a veteran U.S. senator (Richard Widmark). He also takes the senator's beautiful daughter, Diana (Imogen Stubbs). It doesn't matter to Peter that Diana used to be Tim's girlfriend. And it doesn't matter to Diana, either, because true-blue Tim has opted for a low-profile career as a Justice Department lawyer. Diana is nothing if not blunt when she breaks up with Tim: ''I wouldn't be happy being basically a cop's wife.''

Tim winces at the insult but, nobly, continues in his chosen field.

More time passes. Peter graduates from backroom wheeling and dealing, and moves up to networking with the likes of John Palmeri (Mandy Patinkin), a slick but shady character whose business partners are -- well, take another look at his name, and you can figure it out for yourself. Yes, True Colors is that kind of movie.

Screenwriter Kevin Wade took a somewhat more bemused view of working-class ambition in his witty script for Working Girl. In True Colors, however, he repeatedly depicts the self-made Peter as presumptuous at best, amorally opportunistic at worst. He blackmails the senator, betrays his best friend, uses his wife as a stepping stone -- he does all these terrible things because, hey, he doesn't have any class. Worse, he's an ethnic type, though he takes pains to hide it -- he changed his surname from something Polish-sounding to the inoffensively WASPy Peter Burton.

In contrast, Tim, the upper-middle-class smoothie, remains firmly affixed to the high ground. He's held up as some kind of ideal, even when he resorts to some morally questionable methods when taking revenge on his former friend.

True Colors is muddled, but it's quite easy to enjoy as tony junk. The performances -- including Philip Bosco as an amoral senator and Dina Merrill as Widmark's very proper wife -- are very good. Cusack is especially deft at slipping in subtle, almost subliminal, mannerisms that recall Richard Nixon at his trickiest. Herbert Ross directs in a style best described as unobtrusively competent.