Katharine Hepburn, who is a stalk of asparagus herself, compares Spencer Tracy to a baked potato. He was "pure, from the earth, dependable," she says on "The Spencer Tracy Legacy," Hepburn's personal, sometimes too personal, tribute to the great screen actor. It airs as a PBS fund-raising special at 8 tonight on Channel 26, and, transitory excesses aside, it's just great.

A vibrant memorial to the days when movies were movies, as well as a warm and warming screen biography of Tracy, the 90-minute program includes innumerable clips from Tracy's films, even the lowliest of which he lent a galvanizing dignity. Like James Stewart, Tracy always seemed the apotheosis of the Regular Guy, and you felt that beneath the screen image there was a tough, fair, no-nonsense realist. You would have liked him as a friend. You might even have liked him as a father-in-law.

A parade of lustrous reminiscers, in addition to Hepburn, talks about the actor, his craft and his character -- all of which, save for his recurrent alcoholism, seem to have been commendable. Elizabeth Taylor says she called Tracy "Pops" and he called her "Kitten" and that his style on the screen seemed "effortless." Burt Reynolds says Tracy gave him the best acting advice he ever got. Frank Sinatra says that Tracy made dialogue from a script sound "as natural as conversation." Sidney Poitier says that upon meeting him, "I was awe-struck, sk,2 sw,-1 ld,10 actually." Lee Marvin says Tracy had "an unmoving concentration that was just overwhelming."

Hepburn, tottering around the MGM lot, among other locations, pauses to remember the first time she encountered Tracy, much by her design, outside the Thalberg Building. Director Joseph Mankiewicz was there. And Hepburn recalls that "I just stood there, like a goof." These memories are evocatively funny and affectionate. But when Hepburn closes the show by reading a lengthy, gushy, intimate letter she wrote to Tracy more than a decade after his death, the effect is squirmily mortifying.

The clips are superb, whether from one of Tracy's iconographic hits ("Captains Courageous," "Inherit the Wind," "Bad Day at Black Rock") or one of his assorted flops ("Keeper of the Flame," "Up the River"). Hepburn concedes that MGM's lush rendition of "Dr. Jekyll and Mr. Hyde" was, for Tracy, "one of the few times he had laid an egg."

Tracy's daughter Susie shares with Hepburn and the camera cryptic notations from her father's diaries -- for example, "Jean Harlow died. Grand girl." The man was nothing if not unpretentious. Acknowledging the rave "personal reviews" he got for "San Francisco," Tracy added, "Got away with murder."

Precisely what an empty suit like Robert Wagner is doing in this tribute remains vague, and the clips are so tantalizing that you really do want more of some of them, but by and large, "The Spencer Tracy Legacy" is, like the actor and man it celebrates, a true quality item.

'Dress Gray'

Gore Vidal holds forth on Nixonian ethics as they infect a fictitious military academy in "Dress Gray," a superior and gripping two-part NBC mini-series airing Sunday and Monday nights at 9 on Channel 4. The cover-up in this provocative drama involves the drowning death of a cadet who had been, unbeknownst to most of his classmates, homosexual and who died after apparently having been raped by another man.

It may sound lurid, and the dialogue certainly includes words and references rare in prime-time television, but as stealthily directed by Glenn Jordan, it plays like literature. Indeed, Jordan perhaps should have revved things up a bit here and there. Vidal, adapting a novel by Lucian K. Truscott IV, wrote scenes that are unusually long for a TV film, and at times "Dress Gray" comes across like a stage play to which exterior movie sequences have been added.

Then, too, Vidal originally wrote the script as a two-hour theatrical movie. Without commercials, the TV "Dress Gray" runs about 3 hours 20 minutes. The added length includes some padding, but as you're watching it you realize something: A wit's padding is still likely to be better than a half-wit's hackwork. In other words, even when it falters, "Dress Gray" is still of more captivating intelligence than are most TV movies.

Vidal's murder mystery is also a sociological rumination on the sometimes inscrutable behavior of men in groups and a contemplation of what we have come to know -- sometimes with a cold shudder -- as the Military Mind. No, Vidal does not find that phrase to be an oxymoron. Those ever vigilant for left-wing assaults on traditional American values will, despite Vidal's carefully cultivated maverick persona, not find much evidence of one here.

Most of the performances are well up to the demands of the script, particularly that of a young cadet, Ry Slaight, who holds the whole story together and pursues the mystery and the cover-up to their conclusions. The part is played by Alec Baldwin, who here successfully distances himself from the soap opera trap he fell into on "Knots Landing." He's terrifically forceful. And as the film's most conspicuous embodiment of manliness-whatever-that-is, he is, appropriately (or not), the bearer and barer of one of the most ornate displays of chest hair in movie history. After a while, it begins to look like a Rorschach inkblot.

Susan Hess makes a formidable ally as the sister of the slain cadet who is also the daughter of a prominent southern judge. She's a rich girl with a very open blouse who, in the first hour, effectively seduces the hero, who had come to her home with the intention of seducing her.

Lloyd Bridges is his rock-solid old self as the Modern Major General, Eddie Albert plows new green acres as the judge, Patrick Cassidy gives a low-key poignance to the role of the drowned cadet (who lives again in the obligatory flashbacks), and Alexis Smith ennobles the small part of the judge's wife. Unfortunately, though, Hal Holbrook's portrayal of the cover-upping brigadier general seems one long, strutting, growly excess, as much of a caricature as the censoring eagle on "The Muppet Show."

The story spends some time in New Orleans, which gives Vidal a chance for what appears to be Tennessee Williams homage, chiefly through the character of Mrs. Tutwiler, proprietor of the defiantly shady Hotel Voltaire, where only the riskiest trysts occur. Louise Latham is a ripe riot in the part. Although this is hardly one of those glitzy decor mini-series productions, you may be struck in Part 2 by the florid opulence of the judge's home, which is either a magnificently realized set or someone's actual domicile. What a set of digs, indeed!

'60 Minutes'

Last year Diane Sawyer traveled with author James A. Michener on what could be considered the definitively sentimental journey: to the islands of the South Pacific where, during World War II, Michener wrote the Pulitzer Prize-winning novel that became a Pulitzer Prize-winning Rodgers and Hammerstein musical -- the aptly titled "Tales of the South Pacific," of course.

The results of the visit are rewardingly brought home tomorrow night at 7 on Channel 9 as part of this week's edition of "60 Minutes." Sawyer walks and talks with Michener as he makes his first return to the islands in four decades; as he wanders the dirt road that used to be an airstrip built by Seabees; as he renews acquaintance with "a wonderful French dynamo" named Madame Gardelle, now 95 and living in poverty; and as he reminisces about the war and the boys who fought it.

When he sees the ruin that used to be a sprawling plantation home, the place where he did most of his writing, Michener is contagiously moved. "You know, it was a splendid place," he tells Sawyer. "There was festivity. There was gaiety." He breaks up with emotion, then remembers having arrived there at the age of 37, "never having accomplished a damn thing" in his life, he says, and how before long, "this island was my oyster."

The producer of the piece included way too many film clips from the movie version of "South Pacific," a pity in particular since somewhere in the CBS archives there are scenes from the Broadway play recreated for network TV by the original stars, Mary Martin and Ezio Pinza. There is also some very quirky, distracting editing. But then one cut works sublimely well, from Sawyer reciting the lyric "How far away, Philadelphia, P-A" to the same words as sung in the film.

Sawyer appears not to have the problems with Michener, American institution though he be, that she had with Adm. Hyman Rickover during a report last year. With Michener, she seems relaxed and genuine. You don't wish Mike or Morley had gone instead. Still, there is a hesitancy about her, almost an overemphasis on decorum. One may get the feeling she is, to some extent, imprisoned in her own good looks. That notwithstanding, her trip with Michener -- a trip in time as well as in space -- proves eminently worth taking.