IT WAS A ROOMFUL of Washington's black elite -- mostly women but with a sprinkling of men. Doctors and doctors' wives, high-powered professionals and volunteers, perhaps a half dozen Reagan administration deputy assistants, and a millionaire or two. Mercifully, there wasn't much ultrasuede to be seen, and that absence symbolized the spirit of the event. The message seemed to be that the time has come for substance over form, and the audience appeared to be ready.

The occasion was a "Black Women's Agenda" luncheon on Friday, in a hotel a few blocks from the Capitol where the Congressional Black Caucus was holding its annual workshop series. The mood was upbeat, as if the group was on a new track, anxious to be off and running.

What brought the women to their feet wasn't the familiar calls to use their economic and political power for the cause. Instead, it was the almost spiritual connection that sprang up between the trio of speakers and those in the audience and their mutual recognition that the old jargon was out and some hard new balls were going to have to be thrown into the game for the '80s.

So they listened intently to Timothy Jenkins, chairman of the Match Institute, who reminded them that power itself is not corrupt, that it must be used to be effective, and that the elite gathered there have an obligation to use their power to lead.

They listened with surprise to Barbara Williams-Skinner, outgoing executive director of the Congressional Black Caucus, whose speech took a spiritual turn. She challenged them to renew their minds and combine the sophistication of their educational and professional achievements with "the faith of their grandmothers."

"Then the struggle would be over," she shouted. "We have more power than we know what to do with!"

That same theme -- the need for substance over form -- was continued by Patricia Russell of the Federal Communications Commission, who called on the women to save the children.

"We have swimming pools, caterers, personal license tags, and several telephones with those little clicks that interrupt the call we're on to tell us another is waiting. But we must stop being so important and take the time to save a generation of children . . . to tell them what it means to be and to become. Our children are growing up like weeds. We are sending them out onto the highway without a roadmap."

I left those women, exiting into the brilliant September sunshine, wondering if I was simply being romantic, wondering if the spirited applause was merely praise for a dramatic delivery, a job well done. We've always been strong on speakers who bring an audience to its feet.

But turning it over in my mind, I came to the conclusion that something new was in the air, the budding of a collective recognition that it is time to slough off the old mentality.

I came away feeling that those women are tired of having to feel guilty about being part of the "black middle class," that their membership is something shameful. Now they are recognizing that it isn't bad to be middle class, but only to be concerned about form rather than substance.

The musing led me to think about the surprising conclusions about the black elite that had come from two highly recognized scholars, John Hope Franklin, immediate past president of the American Historical Association and a professor at the University of Chicago, and Kenneth B. Clark, the distinguished social psychologist whose testimony on the effect of prejudice on children was cited in the l954 Supreme Court school desegregation decision.

Franklin and Clark cited a prediction made some 40 years before by the late educator-activist W.E.B. DuBois that the time would come when the struggle for racial justice in America would depend upon the contributions of a group of highly trained and intellectually disciplined blacks. Agreeing with DuBois, they said that time has come.

At first I viewed this conclusion with skepticism, even cynicism about DuBois' preoccupation with the role of a black elite. I have always found the concept both disturbing and dangerous. But increasingly, I'm not so sure that this may not part of the road map for the '80s.

At any rate, on a sunny afternoon three days ago, the trained elite was out in force and appeared ready for change. The question to be answered is whether the intellectual discipline will follow.