Former first lady Michelle Obama confessed Tuesday that she used to feel embarrassed by the lack of diversity in Congress every year when she attended her husband's State of the Union address.

Watching from the balcony, Obama said she always did a double-take at the divided Congress. One side, she said, was "all men, all white." The other had some women and people of color.

"At the State of the Union address...one side of the room (is) literally gray and white," Obama said in conversation with TV writer/producer Shonda Rhimes at the Pennsylvania Conference for Women. "On the other side of the room there are yellows and blues and whites and greens. Physically, there's a difference in color."

To Obama, the divide symbolized the failure of Congress to truly resemble the nation it serves.

"We should be working actively to mix it up so we're getting a real broad range of perspectives on every issue. Shoot, I would see that in Congress," Obama said.

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"I look at that and I go, no wonder. No wonder we struggle, no wonder people don't trust politics," she said, adding that diversity is also an issue in companies across the country. "We're not even noticing what these rooms look like."

Obama isn't wrong. The 115th Congress is the most racially diverse in history, but it's still 81 percent white, according to the Pew Research Center. There are 50 black lawmakers in the chambers, alongside 39 Hispanic members, 15 Asians and 2 Native American politicians.

The nation is only 61 percent white, according to the Census Bureau.

Congress is also 81 percent male—only 104 women are in the House and Senate. The nation, by comparison, is roughly 50-50 split by gender.

Top businesses aren't doing much better. In the 16 Fortune 500 companies that make their demographic data public, 72 percent of high-ranking officials are white men.