AMERICA'S film heritage is fading away.

"We're all very concerned," says producer Gary Kurtz ("Star Wars," "Empire Strikes Back"). "It's tragic," 81-year-old director George Cukor says. "It's Hollywood's indifference. They've got guarded their treasures."

They are talking about the problem of deteriorating color in motion-picture film.

Since the early '50s, Eastman Kodak reportedly has controlled 90 percent of the American movie-film market. It succeeded Technicolor, which had dominated the industry from the advent of color film in the early '30s until Kodak came up with a more practical and more economic film base. Unfortunately, decades passed before filmmakers discovered that the new process had serious problems of color instability. By that time, a great many negatives from the '50s and '60s had suffered significant damage.

The decay -- particularly in the original camera (pre-print) negative, but also in release-print stock -- is obvious and graphic. Films like "Tom Jones" and "Lawrence of Arabia" have gradually lost their yellows and greens. Flesh tones have turned vapid, and scenes are turning an unsettling mauve.

Director Martin Scorsese ("Taxi Driver," "Mean Streets") became alarmed about the problem after reading articles in American Film and Film Comment. Now he is spearheading a campaign to force Kodak to develop negative and print stocks that will not, as Variety said in a recent front-page story, "bleed away the 20th Century's film heritage in the dark of a storage room."

The situation, Scorsese warns, has reached "a crisis point and can no longer be ignored. We must act now or the films we make in the 1980s will be subjected to the same indiscriminate destruction as those made in the past 40 years. Working this way is insulting and insane." More than 150 major directors, actors, actresses, distributors and exhibitors signed his petition to Kodak.

Scorsese charges that Eastman is responsible "for the destruction of our past and current work. They will have to account for the conscious perversion of the future history of cinema."

However, Kodak has always printed a stability disclaimer on its film containers. And in fact, film used for exhibition prints (as opposed to negatives) is expected to fade. "They are designed for the fun of the movie," says Henry Kaska, Kodak's corporate communications director. "Its physical life-expectancy is one year, or 200-300 showings. It's not intended for long-term storage and does not need the stability characteristics built into other films." The High Cost of History

Earlier this week, Scorsese took time for editing "Raging Bull" (which has Robert De Niro as boxer Jake LeMotta, and which the director chose to shoot in black and white) to meet in New York with Kodak representatives. It was basically an information meeting, with more intense follow-ups expected. Scorsese is also expected to organize an industry-wide symposium in September with manufacturers, producers and filmmakers.

"There are two basic issues here," says writer-director Paul Schrader ("Blue Collar," American Gigolo"). "How do you save what's on the verge of being lost and how do you prevent things from being lost in the future?"

In general, the industry wants most of its money out of pictures on initial release, and the studios have not shown much inclination to preserve the pat -- except for Disney and MGM. Disney's family-oriented films have a new audience every seven years, so it is sound business sense for them. MGM has always had a policy of preservation. It paid off handsomely with "That's Entertainment," the musical compilation of old movies that has grossed more than $12 million.

But now the problem has become serious for the all studios -- both because of the continuing earning power of blockbusters like "Star Wars" ($235 million in domestic and foreign receipts by late 1979) and because of the importance of selling both new and older products to color television. In 1974, when NBC paid $5 million for a single showing of "Gone With the Wind," they reportedly had to spend a significant amount of money enhancing the original colors that had begun fading on the negative. Preserving black-and-white footage is far less complicated than color, according to American Film Institute archivist Larry Karr. He points out that the major archival effort of the last decade has been to transfer footage from nitrate stock (the highly flammable, perishable material on which most older, black-and-white films were shot) to tri-acetate safety stock. "With nitrate we have the technology," he says. "What we don't have is the money. With color we don't know what to do other than keep the films in cold storage, which slows the process.

Cold storage, in which negatives are kept in vaults close to freezing temperatures with a humidity of 25-30 percent, is probably cost-effective since the alternative involves the striking of three different black and white separation negatives which can then be re-assembled to provide a copy negative. s

The cost per film is $15,000-30,000, with another $5,000-$15,000 for a test print to check the quality. Since even a single frame's absence from one of the internegatives can thrown a picture out of synch, this can be an expensive process. MGM, with its long history of conservation, protects all elements of all its pictures, excluding television series. It not only does separations but keeps duplicate copies in an abandoned Kansas salt-mine where they have built an additional refrigerated vault for special situations. The State of the Art

But even that is not enough for directors like Scorsese and Schrader. While Gary Kurtz insists that "more and more filmmakers will be able to convince producers that it's worth everyone's while to go to black and white separations," the Director's Guild of America will most likely have to force the issue in its upcoming negotiations by pushing for what Scorsese refers to as a "color preservation clause." At this time, very few directors have sufficient negotiating power to insist on getting separation negatives made for their films, and as Karr admits, it's hard to argue for special treatment with over-budget films and independent producers. Those with power, particularly the younger directors, have taken to having internegatives made of their own films, but, says Schrader, it's still a small number, and with problems of piracy, studios are not anxious to have negatives or prints outside of their control in general circulation.

When color first started to be used in film in the mid-'30s, Technicolor had a virtual monopoly. Their heavily saturated colors were at first used mainly in musicals and action/adventure/costume epics. Over the years, those colors have lost little of their quality when handled carefully. But that process (called imbibition) entailed the use of bulky cameras and the expensive processing of four rolls of film: three for the primary colors and a fourth for the soundtrack. The resulting prints were, according to Karr, "stable [many of the prints remain in mint condition] but were economically unfeasible with the changing style of theatrical releases, print runs and cheaper color technology."

In the early '50s, Kodak came out with Eastmancolor -- a single strip containing the primary colors. Among other advantages, it was cheaper. That was what producers were after, and Eastmancolor swept the industry -- so much so that Technicolor closed its last imbibition plants in the late '70s and converted to the new process. But Eastmancolor's combined negative-positive process required some compromises in color quality, and one of them was dye stability.

Research is currently under way to develop alternative reconstruction techniques, ranging from video to holograms. But as AFI's Karr says, "there is something intrinsically valuable to an original negative --any transfer will lose some quality." Adds Roger Mayer, head of MGM's laboratories, Scorsese's campaign "may have a very positive effect in getting producers to realize the value of some of their corporate actions." Among Scorsese's demands are that Kodak produce a release print stock equal to the now-defunct Technicolor imbibition process.

Kodak is now manufacturing a new series, LF, with a 10 percent price premium and a life expectancy, according to Kaska, dozens of years longer. Kodak has also developed a system for restoring faded color transparancies, a process Kodak's Henry Kaska says is "technically possible " to adapt to negatives. It's the deterioration of the negatives that is of most concern to the filmmaking community. As long as the negatives are in good shape, then quality prints can be made. Once the negative is destroyed or damaged, there is little to be done. Future Fadeout?

In the next decades, film buffs will be able to compare, say, Francis Ford Coppola's "Godfather" films (processed in Technicolor) with "Apocalypse Now" (which was not) -- or European prints of "Stars Wars" (among the last Technicolor films) with "The Empire Strikes Back." Of course, there are dozens of protection negatives on those and other blockbuster films. The less successful movies are the more endangered: "Films that are not continuing sources of revenue are being lost," says Schrader. "We don't know which are the ones future generations will want to see."

In the meantime, it is economically impossible for many studios to salvage their considerable backlog of films at $30,000-$45,000 each. It would take 20 years and an incredible amount of space for the reels of negatives. According to Mark DelCostello, Scorsese's assistant, "We feel the ultimate answer to preservation lies with government agencies. It may be bureaucratic, but the government will be around a lot longer than the producers and the industry."