Registering colors as trademarks has generated controversy in the food, agricultural and other industries.

As recently as 1995, the U.S. Supreme Court unanimously held that color alone can meet the basic legal requirements for use as a trademark. In the Qualitex Co. v. Jacobsen Products

However, other attempts to use color as a trademark have been less successful.

The language of the Trademark Act, which gives a seller or producer of goods or services the exclusive right to register a trademark, is broad. The courts and the U.S. Patent and Trademark Office have authorized trademarks for such diverse symbols as the:

* scent of plumeria blossoms on sewing thread;

* shape of a Coca-Cola bottle;

* sound of NBC's three chimes.

Perhaps the most well-known color trademarked for a product is the pink used in Owens-Corning fiberglass insulation.

To register a color as a trademark, basic legal requirements include the ability to serve as a symbol or device that distinguishes one seller's goods from those manufactured or sold by another. In other words, the color must represent the source of the goods.

If a color describes a product such as orange juice it cannot be trademarked because it does not identify its source. For example, the color orange cannot distinguish one seller's orange juice from another's because orange juice is orange.

Although the color orange may not be registered as a trademark for orange juice, it might be protectable as a mark for goods such as radios.

Color as a trademark can play a significant role in marketing goods. However, the courts will restrain this exclusive right if it unfairly restricts competition.

Patent law guarantees an exclusive right of limited duration for new inventions. As a consequence, a functional feature of a product cannot be a trademark.

If color is essential to a product's use or purpose, or affects the cost or quality of the goods, it may not be protected as a trademark. The exclusive right obtained through a patent is for a limited time -- 20 years from the patent application fling date. However, the exclusive right associated with a trademark endures as long as it is properly used as a trademark.

In the Brunswick Corp. v. British Seagull Ltd. case in 1994, a lower court decided that black cannot be registered as a trademark for outboard boat motors. The court found that black is appealing to consumers because it can make a motor appear smaller and it is compatible with various boat colors.

The court reasoned that granting exclusive use of black for motors would put competitors at a disadvantage unrelated to the product's reputation.

It has also been argued that there is a limited supply of colors that will quickly be depleted if they are protected by trademark.

The Supreme Court decided in the Qualitex case that when the color supply is threatened, a color is considered functional for the product and cannot be trademarked. The Court reasoned that exclusive use of a color when colors are scarce unfairly places competitors at a disadvantage unrelated to reputation.

Trademarks aim to reduce a customer's shopping costs and time spent making purchasing decisions. The mark should symbolize that an item is made by a certain manufacturer so a consumer will recognize it as desirable or undesirable.

Trademark registration rights also protect the consumer. The laws reduce chances that a seller will use a mark, confusingly similar to one on better quality goods, to mislead customers into buying inferior products.

Richard C. Peet is an attorney with Foley & Lardner, 3000 K. St., N.W., Washington, D.C., 20007-5109, USA; 202-672-5483, fax 202-672-5399.