Youth officials in Maryland and nine other states have complained to the Coors Brewing Co. about its new colorless drink, which tastes like soda pop and has inspired rumors that it cannot be detected on police breath-testing equipment.

Coors has sent strong letters to police chiefs and school superintendents emphasizing the alcoholic content of the beverage, called Zima, and assuring them that the rumors are false.

But national experts on underage drinking say Zima's sweet, smooth taste and lack of color make it difficult for police to identify and easy for teenagers to consume in large quantities before its alcohol content -- higher than beer -- takes full effect.

"It is a very misleading alcoholic beverage," said Kae McGuire, associate director of the Trauma Foundation of San Francisco General Hospital. "It tastes like Seven-Up."

Maryland officials say they have been forced to take extraordinary measures, including videotaping a Takoma Park police officer as he voluntarily got drunk on Zima, in order to squelch misinformation about the beverage.

"It doesn't have the odor that beer has, and that is a big problem," said Nancy G. Rea, coordinator of Montgomery County's Drawing the Line on Underage Alcohol Use program. "How do you know if it is alcohol?"

Officer Mary Carlin of the Montgomery County division of the Maryland-National Capital Park Police said park police officers began finding unruly teenagers drinking Zima last spring, shortly after it was introduced. Some of the youths insisted it was not alcoholic, or at least not detectable on a Breathalyzer, Carlin said.

When officers visited the homes of the inebriated youths, Carlin said, the parents "didn't even realize what they were drinking was alcohol."

Jesse Rivkin, a 16-year-old junior at Bethesda-Chevy Chase High School, said he had sampled Zima and thought its smooth taste attracts problem drinkers. "It tastes like Sprite," he said. "It goes down very easily and so a lot of kids tend to abuse it."

He said at $6 per six-pack, Zima was more expensive than some beers and more common at parties frequented by wealthy Whitman High School students.

A Whitman senior who asked not to be identified said its smooth taste drew young people who wanted to get drunk but didn't like the taste of hard liquor. "I think it's more popular with girls than with boys," he said.

Police said they are concerned not only about the new beverage's allure but the problems it may pose in prosecuting those who sell or serve liquor to people under the legal drinking age of 21. Carlin said a defense attorney might ask the arresting officer if he had sufficient cause to investigate: "How did he know it was an alcoholic beverage? It didn't look like it, it didn't smell like it."

Rea said Zima has an identifiable, if unusual, smell. She said officers should be able to justify such arrests once they have some experience with the beverage.

Each bottle of Zima is labeled "unique alcohol beverage" and carries the government health warning, but Maryland officials said Coors declined to change an initial advertising campaign that they said added to the confusion by portraying Zima as an intriguing mystery drink.

When Rea's program, part of the county department of family resources, and the park police contacted Coors, Carlin said, the Colorado-based beverage company "at first was defensive." But the company soon provided a strong letter signed by Janet Rowe, Coors's manager of corporate communications.

In boldface print, the letter said, "Zima, like any alcohol beverage, contains ethanol -- the ingredient that registers in any Breathalyzer test. Zima, like other clear alcohol beverages -- vodka, gin, rum -- is still detectable despite its clear profile.

"As an exciting new product and topic of conversation, misperceptions and inaccuracies about Zima sometimes occur," the letter said. It identified Zima as "a whole new category of alcohol beverage" and as "a moderate alcohol beverage with the same alcohol content as beer, at 3.7 percent by weight."

Carlin said she appreciated the letter, but noted that Zima is 4.65 percent alcohol by volume, the other way of measuring alcohol content, compared with 4.2 percent for a Coors light beer.

Rowe said in an interview that the rumor that Zima would not show on a breath test "popped up in at least 10 states." She said "we sent out the letter every time we got more than two calls from the same zip code." Copies went to the mayor, police chief, school superintendent and district attorney in each area. All the states affected, she said, were east of the Mississippi River.

To dramatize the point that Zima's effects can be detected, Takoma Park Police Officer Mark Gardner consumed several bottles while Carlin recorded his increasing blood-alcohol level on a Alco-Sensor preliminary breath testing device. Videotapes of the demonstration made their way onto local television news programs in Washington and some other cities.

Brandy Anderson, spokeswoman for Texas-based Mothers Against Drunk Driving, said the organization was studying the packaging and marketing of Zima as well as other newly popular college campus drinks to see if they promote underage drinking. Anderson said the group is looking at "Jell-O shots," also known as slime balls, which mix alcohol with Jell-O, and tube drinks -- fruit juice and alcohol mixes served in test-tubes by waiters wearing white laboratory coats. Carlin said she suggested that Coors change one of its initial ads so that two confused young men given Zima in a bar in an alternative universe are first asked to prove their age. Coors instead has continued to air a general ad warning against underage drinking. Its new Zima ads, "Zomething in Common," show Zima drinkers of every size and nationality, all played by actors who, under alcohol industry rules, must be at least 25 years old.

The company said it is testing in two markets an amber-colored, slightly more alcoholic drink called Zima Gold for those who want a "bolder" drink. CAPTION: MALT BEVERAGES SALES IN 1994 Zima: ............................. 1.3 million barrels Budweiser (U.S. sales leader): ... 41.4 million barrels All malt beverages: ............. 190.2 million barrels SOURCE: Beer Marketer Insight