Judging from the elbow-to-elbow crowds in discount consumer electronics stores, this is going to be a record year for color television sales.

The reasons why aren't hard to fathom. Customers entering one such store in Northern Virginia are confronted with a wall full of TVs with prices sliced to the bone.

For the consumer, it is a triumph of competition. The sets come from a dozen manufacturers, American, Japanese and South Korean, who are locked in a bidding war that shows no sign of ending.

But for the American companies -- RCA, General Electric Co., Zenith Radio Corp. and North American Philips -- that wall loaded with rival products is a maddening reminder of the competitive carnage the industry has suffered over the past two decades.

In 1968, there were 18 manufacturers of television receivers in this country, all U.S.-owned. By 1980, there were 13, and only four of them were U.S. companies.

The reasons for the rout of the American television industry have been fought over for more than a decade, in courts, before government trade agencies and in newspapers and academic journals.

Now the issue has reached the U.S. Supreme Court again, in the form of a 14-year-old antitrust suit pitting Zenith against the Japanese television makers, their American subsidiaries, and several independent distributors of the Japanese sets in this country.

Ancient though it is, the Zenith case illuminates some of the most important issues underlying the current economic and political debate over trade.

Zenith charged that, beginning in the 1960s, it was the victim of a conspiracy by the Japanese companies, which allegedly collaborated on a detailed strategy to penetrate the American market.

A U.S. District Court held that for various reasons, a large part of Zenith's evidence was not legally admissible. The evidence that remained wasn't enough to establish the existence of a conspiracy, the district court concluded, and it granted the Japanese manufacturers' request to dismiss the suit.

But the U.S. Court of Appeals for the 3rd Circuit reversed that decision.

In the appellate court's view, it was reasonable to conclude from the evidence that the Japanese manufacturers (except Sony) had conspired to fix substantially lower prices on their sets sold in this country than on comparable sets sold in Japan.

The court read the evidence to show that the Japanese companies 20 years ago agreed to stabilize prices for their TV sets in their own country, to avoid a crippling price war on their home front. The Japanese government protected them by keeping out foreign TV sets -- including Zenith's.

Second, the Japanese companies established minimum prices for the U.S.-bound sets through formal written agreements, and gave systematic, secret rebates to U.S. distributors to increase their price advantage over U.S.-made sets.

In effect, the Court of Appeals sided with Zenith's contention that a two-tier pricing system had been created -- higher prices in Japan, and lower prices in the U.S. market.

The Reagan administration's antitrust division has challenged that view, asking the Supreme Court to reject the Court of Appeals' findings, uphold the District Court and have the Zenith's case thrown out.

The argument, however, isn't over the facts in the case, but rather their meaning.

There was a pricing agreement in Japan, backed by the government, which protected the Japanese TV industry from foreign competition as it grew into a world-class power. But Deputy Assistant Attorney General Charles F. Rule told the Supreme Court recently that if anything, that was a violation of Japanese antitrust laws, not American.

There were arrangements to set minimum prices on TV sets shipped here, and to limit the number of U.S. distributors through which the Japanese companies could sell their sets.

But Rule argued that these were arrangements imposed on the Japanese manufacturers by their own government and that what these agreements did was keep the Japanese companies from cutting their U.S. prices even further. The Japanese government, you see, was afraid of trade reprisals by Washington if Japanese TV set prices fell too low.

When the Japanese companies cut prices anyway, The Japanese government, you see, was afraid of trade reprisals by Washington if Japanese TV set prices fell too low. through the secret rebates, they were behaving the way competitors do, not conspirators, Rule argued.

The U.S. manufacturers did face a severe challenge from low-priced Japanese sets, and the Japanese government was deeply involved in the competition. But that doesn't constitute an antitrust violation, the administration contends.

"The allegation was that there was a cartel to hold up prices in Japan and an arrangement to promote exports to the United States at lower prices," said Assistant Attorney General Douglas H. Ginsburg. "In other words, it was an arrangement to benefit American consumers through low prices."

The suit "was brought by competitors against their foreign counterparts because of low prices to consumers, and I tell you that's a perversion of the antitrust laws," Ginsburg said in an interview.

It is easy to understand the pain that has eaten way at Zenith's top management for more than a decade as they waged their uphill struggle against the uniquely cooperative relationship established by the Japanese companies and their government.

In contrast, as Zenith fought its crusade before American courts and agencies, it often confronted the representatives of the U.S. government on the opposing side.

One conclusion is that the Japanese benefit from a system finely tailored to their national economic goals.

Zenith fared far worse at its government's hands, but its treatment probably reflects a national economic understanding in this country, too -- the political consensus that puts consumers' interests ahead of companies'.