"No one's wearing a dashiki," said Carl Holman, president of the National Urban Coalition, last night with a smile. "They used to say it was all surface with us. But this is very serious."

Holman was gazing at the receiving line where the president of Liberia, Dr. William R. Tolbert Jr., stood in a white uniform, flanked by his foreign minister, greeting guests who flowed through the Palladian Room of the Shoreham Americana Hotel.

A round of hors d'oeuvres, business suited men and well-dressed women talked in groups.

The African diplomats, State Department officials, lawyers, counsultants and congressmen -- such as Charles Diggs [D-Mich.] and William Gray [D-Pa.] -- were all talking issues at the reception given by the black lobbying group TransAfrica for the visiting Liberian head of state.

"What Charlie Diggs started and Andy Young furthered is going to continue," said Holman. "That's nice to see."

What they started was the interest and activity of blacks in foreign policy, particularly Africa, and that's what the two-year-old group TransAfrica continues. "Our job is to express to the Congress, the administration and the president the views of black America on foreign policy," said TransAfrica executive director Randall Robinson, brother of newscaster Max Robinson [also there last night].

President Tolbert, who is also chairman of the 49-nation Organization of African Unity, addressed the U.N. General Assembly last week and is expected to meet with President Carter today.

"We'll talk about matters in Africa in general and in Liberia," said Tolbert. "There are always problems to be looked at in a global way."

Tolbert is also expected to discuss the issue of Zimbabwe-Rhodesia, whose new black government is being challenged by nationalist black guerillas. Almost no African nation -- except South Africa -- supports the current government.

Tolbert also met with officials of B. F. Goodrich and Firestone -- companies with interests in Liberia -- in the Midwest last week.

Andrew P. Miller, Liberia's business agent in this country and a former contender for a Virginia Senate seat, was also there last night.

Tolbert met with Rep. Parren Mitchell [D-Md.] yesterday to discuss American minority businesses going to Liberia.

Rep. William Gray, secretary of the Congressional Black Caucus and a member of the House Foreign Affairs Committee, slid into the reception shortly after Tolbert left. "Just maintaining my ethnic tradition of digital differentials," he quipped.