The latest U.S. postage stamp commemorates civil rights leader Whitney Moore Young Jr., who died 10 years ago on a visit to Africa. The 15-cent stamp, issued yesterday, shows Young sitting at his desk, painted in a bold, heroic style and printed in six colors. It would make a fair poster.

But it makes another mediocre postage stamp.

Postage stamps have been called the nation's calling cards. They represent the nation's pluralism in the multitude of noble sentiments and causes they expound. But I hope they do not represent the nation's taste.

The trouble is that the Postal Service does not think of its stamps as graphic designs to meet their purpose. The purpose is to tell the mailman that the cost of delivery has been prepaid.

The Postal Service thinks of its prepayment certificates as miniature billboards for all sorts of messages intended to please humanity in general and stamp collectors in particular. The confusion of purposes confuses the design.

Confused design is confusing design and therefore bad design. It permeates the entire United States government. In general, the U.S. government has not yet understood the enormous importance of good, strong, simple and consistent design -- of everything from postage stamps and stationery to courtrooms and federal buildings -- as a means of conveying a good, strong, simple and consistent image.

Responsible officials who know that sloppily dressed government clerks would undermine public confidence in their agency do not know that sloppily designed posters do the same.

In contrast to the impressive and consistent graphic image conveyed by the Swiss or the British governments, U.S. government design is utterly uncoordinated. Every agency does more or less as it pleases, and most attach little importance to design and effective communication. The visual gobbledegook is as bad as the verbal gobbledegook.

The nation's professional designers and the Design Arts program of the National Endowment for the Arts are trying to improve matters. They have managed to give the U.S. Labor Department a new graphic look. But their success in general has been less than spectacular, particularly with the Postal Service.

Look around your unfriendly neighborhood post office.The lumpish posters, the unprofessional lettering on signs and announcements, the dopey cartoons and the mostly tawdry decor range from the mediocre to the offensive.

Luckily, the Postal Service, whose annual payroll equals that of the United States Army, cares a little more about the 30 million stamps it prints every year. It cares because millions of stamp collectors are so passionate about these colorful little pieces of paper. Last summer, one of them paid $240,000 for a 1-cent U.S. postage stamp, cancelled in 1869. With each new issue, the Postal Service also makes a tidy sum from the hobbyists.

Stamp collectors are rewarded for their devotion. Of the 15 members of the Citizens Stamp Advisory Committee, which was established in 1953, eight are philatelists. The chairman, Belmont Faries, is a former editor and philatelic writer of The Washington Star. The other members are a historian, a filmmaker, an educator, writer James A. Michener, National Galley of Art curator Douglas Lewis, the director of the U.S. Bureau of Engraving and Printing (which prints most stamps), and only one professional graphic designer -- Howard E. Paine, the art director of the National Geographic Society.

The primary function of the committee is to screen some 1,500 ideas for stamp topics, submitted to the postmaster every year. Most of them come from special interest groups. An example is the Whitney Moore Young commemorative stamp, which is one of four stamps in the "Black Heritage USA" series. Another example is the "Architecture USA" series, which the nation's architects lobbied for.

Stamps are issued to tell us (under a portrait of a gentle eagle) that "Organized Labor [is] Proud and Free" or (surely the least attractive design in all Christendom) that "Wise shoppers stretch dollars -- Consumer Education." Wisely, postal shoppers are not told the price of that one. But stamps do tell us to give blood, plan our families or support our youth. They promote folk art, windmills, historic events and buildings, and prominent Americans who must be dead for least 10 years.

Having ascertained the worthiness of the topic or person and the accuracy of the claims made or implied or them, the adivsory committee, which meets six times a year, forwards some 15 ideas to its design coordinators, Bradbury Thompson, a well-known typographer, and Steven Dohanos, a well-known illustrator. Between them, the two have designed about 60 stamps. They pick an artist from what they call their "talent file" of interested artists, who are asked to translate the idea into a drawing or painting for the consideration of the advisory committee. The fee is usually only $1,000, but the commission is so prestigious that nobody has ever refused.

The postmaster has the final word, and everyone in the process is much concerned that the topics and the artists are fairly distributed geographically, that the designs can be easily reproduced and, most of all, that no one is inadvertently offended.

Nobody but Howard Paine, who joined the committee only a few months ago, seems to worry much how the ultimate product looks on an envelope, how well it performs its basic function and how the general consumer likes it.

Only recently has the advisory committee established a consistent style for the essential information on stamps: It is "USA" now, not "United States" or "U.S." It is "15c" rather than "15 cents." But many stamps are still cluttered with far too much berbiage. Others are oversized and get in the way of the address, particularly on postcards. Some portraits look to the right, as though looking for a chance to escape from the envelope on which they have been pasted. No one ever seems to have thought of cancelling stamps without spoiling their looks.

At a recent panel discussion on stamps, art curator Lewis deplored the poor reproduction of paintings by such masters as Memling, Raphael or Goya used for Christmas stamps. (Whatever happened to the separation of church and state?) Actually, the Bureau of Engraving and Printing's color work is highly sophisticated. The problem is that a large canvas must be redesigned by cropping, simplifying or other distortions to be intelligible on a tiny piece of paper. You cannot simply miniaturize it any more than you can enjoy Beethoven's Fifth Symphony in 10 minutes by speeding up the tape recording. When you tamper with the scale of a work of art you distort it.

In other words, we can have either art or stamp kitsch. We cannot have both.

Howard Paine, a graphic designer with a wide-ranging interest in science and history, set forth some design principles that should be the beginning of a guidebook for stamp design.Stamps, he said, must be designed as stamps and not as reproductions of something else. His slides showed, for instance, that portraits on stamps work best when they are close-ups rather than long distance shots framed by an elaborate cartouche.

Lettering on a good stamp, Paine said, is integrated with the rest of design rather than just put into the margin. He did not quarrel with the use of stamps as the nation's advertisements to itself. He just wants them clear and effective.

Paine would undoubtedly agree with one of the country's greatest graphic designers, W. A. Dwigging, who wrote in 1932: "The size of postage stamps suggests that its most practical work-out would be in the form of a spot of clear color printed flat. This quite small area on the corner of an envelope is likely to tell better as color than as linear designs."

In any event, there is room for improvement.