Will audiences consider James Cagney a dandier "Yankee Doodle Dandy," find more appeal in "Camille," sign up in greater numbers for "Mutiny on the Bounty" and shiver more to "Dr. Jekyll & Mr. Hyde" if these black-and-white movies are presented in color?

MGM/UA Entertainment Co. will find out later this year when it offers electronically colored versions of these old favorites to see if the best market for them is syndication for standard TV broadcasts, cable broadcasts or videocassette sales and rentals.

Under a contract with the motion picture company, Color Systems Technology Inc. of Los Angeles will convert videotape copies of the movies using patented technology invented by its chairman, Ralph Weinger. It also has a contract to supply Warner Amex Satellite Entertainment Corp. with up to 20 converted films. A slightly different process is being used by Colorization Inc. of Toronto, 35 percent of which is owned by Hal Roach Studios.

Color Systems expects entertainment companies to embrace its technology so they can earn more money from old movies and television shows that aren't being marketed now because they can't compete with those that were made in color.

Color Systems' executives are painting their forecasts a bright green -- just like money. They estimate that there are 2.79 million minutes of black-and-white movies and television shows produced in the United States alone that are likely candidates for conversion to color and that, even if Color Systems won contracts to work on just 10 percent of this total, the company would be kept busy for 15 years. Added to this is potential work from the libraries of black-and-white films and recorded television shows produced overseas.

Weinger said he first thought of coloring black-and-white movies and television recordings in 1960, when he was designing color television test equipment. He said that shows were being broadcast in color for only a few hours a day then, and that he noticed how some out-of-adjustment sets partially colored black-and-white broadcasts. He set out to do this deliberately, but found no industry interest in the innovation until 1975, when "the market shifted and technology caught up" with his plans.

As is often the case these days, the key to this innovation is computers.

The black-and-white film or videotape is copied on broadcast-quality videotape, and key frames of each scene are displayed on a computer screen, allowing artists to electronically "color" the scene.

The computer stores electronic information on the color of each area of the frame and then automatically continues those colors on subsequent frames of that scene. Artist-technicians must color-code each new scene and object that come into view. They link a particular color from their electronic palette with a particular shade of gray in one object in the original.

Color Systems maintains a staff of researchers to determine what color certain things should be. "There are things that must be historically accurate," said Buddy Young, the company's president. A staff of researchers determines what color is correct for things such as "uniforms, flags and Clark Gable's eyes," while other colors are "blended in aesthetically," Young said.

Outdoor action/adventure movies and TV shows, musicals, features for children, and those linked to holidays are prime contenders for electronic coloring, according to Color Systems. But the company and its competitors may never bring the rainbow to other offerings.

"There are some pictures that we very well may decide aren't going to be enhanced by color," said MGM/UA Senior Vice President Roger Mayer, citing most of Woody Allen's movies, which he said were intended to be black and white.

He also noted some dispute in the industry over whether "Casablanca" should be converted to color, indicating that some people have expressed doubt that the popular movie would attract any more viewers that way. "At this point, I would not think of a movie that we wouldn't touch," Young said, explaining that a viewer who took offense at a color version of "Casablanca" could tune the color out.

A broader question was raised by Amy Turim, an assistant archivist with the American Film Institute. Turim said that archivists are "not quite so positive" about the concept of electronically coloring films, because "it's playing with something that wasn't meant to be. Generally, the view of the archivist is to preserve what there is" in the best possible condition.

Nevertheless, Mayer said that MGM/UA expects to receive color versions of the four films by late spring. The company also has a contract with Colorization. Mayer said that the competing processes create the same results but that Colorization's personnel are "further ahead in their ability to produce at this time."

As for Color Systems' process, Mayer said, "I think it's pretty good. . . . I think it can be improved [and] will be improved."