Speakers at a plenary session on diversity — the first on that topic ever held at a Council on Foundations conference — sparred over legislation in California that would require big foundations to publish information about the race and gender of grantees, staff members, and board members.

Foundations must do more to improve their track records on diversity, but legislative solutions are “fraught with sandbags and land mines,” said Robert K. Ross, president of the California Endowment, in Los Angeles. He noted that the California bill, adopted by the California Assembly in January, ran into trouble because it was amended to require foundations to provide data about sexual orientation, which then drew complaints about violating privacy rights.

“There is no model definition of diversity,” said Mr. Ross, who also heads the Diversity in Philanthropy Project, a group of about 40 foundation leaders who are pushing for more diversity in the field.

But Ann Wiener, a trustee at the Jessie Smith Noyes Foundation, in New York, said after some tough discussion her board voted overwhelmingly to endorse the California legislation. She said the foundation world had not come very far on a voluntary basis and “legislation may be the only way to do it.”

The council presented data showing that 87 percent of foundation boards, and 94 percent of chief executives, were white in 2006, compared with 66 percent of the general population.

Rep. Xavier Becerra, a Democratic member of Congress from California, said foundations might invite federal scrutiny if they do not step up their giving to projects that benefit minorities, saying they have an obligation to earn their tax subsidies by working for the public good.

Mr. Becerra called the tax deductions that people claim for charitable donations a “$32-billion earmark” and noted that Congress is seeking ways to rein in spending. “Right now earmarks are under a big microscope, and $32-billion is a lot of money, so do well.”

Adam Meyerson, president of the Philanthropy Roundtable, a group of mostly conservative grant makers, said he rejects any effort to tell foundations how to make up their staffs, boards, or giving. He said there’s no reason to assume a white-dominated board won’t care about helping low-income or minority people.

“There’s a tremendous yearning among current and especially among prospective new donors to make a difference in the lives of low income children and families,” he said. “Let’s not drive away the new philanthropic capital by taking away from donors the freedom to decide how and where to give away their money.”

I. King Jordan, a deaf member of the board of the Theodore R. & Vivian M. Johnson Scholarship Foundation, in West Palm Beach, Fla., urged the grant makers to pay more attention to physical disabilities when they discuss diversity.

“We have to be inclusive in our definition of diversity. I feel like I’m standing out like a sore thumb at this conference,” he said. “I’m the only deaf person in the whole conference.”