In her former role as first lady, Michelle Obama veered clear of speaking about fashion so as not to deter from her work, but now she has shared her views about style and its significance in-depth in a special edition of “20/20” with ABC News’ Robin Roberts.

Whether discussing designing her prom dress, making fashion choices with inclusivity in mind, or dealing with public scrutiny about her clothes, the decision to get bangs or to bare her arms at a State of the Union address, she doesn’t hold back. With Rihanna’s “Diamonds” playing in the background of the hourlong show, Roberts highlighted her fashion evolution from a working mom to first lady and post-White House author and advocate, and how “behind every look, there is a message.”

During her time as first lady from 2009 to 2017, Obama covered a lot of ground, taking 22 international trips and visiting 36 countries. The University of Pennsylvania graduate, who earned a law degree at Harvard, gave her White House wardrobe a good amount of attention, despite previously preferring not to talk about that. More than any other first lady, her attire was made up a wide array of styles from American designers from the firmly established to up-and-comers.

Along with footage of her donning a Naeem Khan gown for her first state dinner in 2009 and choosing a rose gold Versace one for a 2016 state dinner, there are shots of her husband Barack Obama in the black tuxedo that he wore for formal occasions during his eight years as president. Obama referred to her gown as “working gowns,” given the long hours they were worn for, as well as the amount of standing and glad handling that was required at formal affairs. As a sign of how she never wanted her clothing choices to inhibit her, there are snippets of her taking part in a pushup contest with Archbishop Desmond Tutu in 2011.

The rare sit-down network interview coincides with the release of Obama’s new book “The Look,” which was written with her longtime stylist Meredith Koop. The former first lady was interviewed by Roberts on the campus of Marymount University, which is near the Obamas’ home in the Beltway. Sizing up her White House years, Obama said, “I wanted to show up with thought and consideration.”

As for why she decided to take a deep dive into fashion and style now, Obama noted how during her eight years in the White House, “There was a lot of attention, um, given to my fashion, my physical appearance, all of that, I made it a point to shy away from that conversation, because I was worried that it would become a distraction. I wanted to make sure that as the country got to know me, they’d know me by the work that I did and not what I looked like.”

Now that the country knows Obama for herself, she said she felt the time was right to talk about “the fun stuff.” As for fashion being a “soft power,” the 61-year-old said, “You know, style and fashion, and how we show up in the world is an important way that we send a message. What you’re wearing says something about what you care about. It speaks to your background, your culture. So, I really thought about what I wanted to say.”

Acknowledging how she has never felt more confident and beautiful than she does now, Obama said, “You know, there’s something about the 60s. It is the best time of my life now that my daughters are launched and doing well. Um, my husband’s settled. There’s a certain freedom that I feel I’m at that stage in life where I can say, ‘Yeah, maybe I know a few things.’”

Viewers caught glimpses of her childhood self in Chicago, where she sported clothes that her mother had sewn or that were bought at Sears. They also heard how she always wanted white patent leather go-go boots instead of winter boots, but her mother nixed that plan with rubber boots that won over shoes. There was also a shot of her prom dress, which was made from a Buttermilk pattern that she had chosen strategically — the vertical buttons on the side could be unbuttoned once out of the house for a “sexier” look.

Recalling how her fashion became more intentional during the 2007 presidential campaign, which called for at least five rallies a day on average. She told Roberts, “I need to be able to throw a cardigan on, put a heel on, take a heel off, put a flat on. So, a lot of what I learned was the practicality of getting dressed.”

After Roberts noted how Obama had said, “’We were all too aware that as a first Black couple, we couldn’t afford any missteps.’ And that ‘As a Black woman, I was under a particularly white hot glare,’” Obama said, “Making a mistake in a political environment where you’re the first and people are where your opponents are using your race as a fear-based strategy to make you seem like the other, then everything matters.”

Allowing how every first lady faces the public scrutiny and very woman in the public eye faces a certain level of scrutiny because of her physical appearance, Obama said, “We live in a culture, sadly, where, you know, if somebody wants to go after a woman, the first thing they do is go after our looks, our size, our physical being, um, as a way to, you know, make us feel small, to keep us in place. And as a Black woman, I was dressing for all the, the mothers and grandmothers out there who I knew would be shaking their head if I didn’t, if I didn’t show up right,”

Diane von Furstenberg, Jason Wu, Tracy Reese and Narciso Rodriguez are featured in the program, as is The New York Times’ fashion director and chief fashion critic Vanessa Friedman. Roberts also played a few video messages, including one from Reese, who spoke of the great pride she felt whenever Obama wore her designs. Early on non Furstenberg said of Obama, “Her style, she owns it. She embraces the moment.”

Koop spoke of her reputation for asking many questions, including ones about the time of the event, the crowd, the number of attendees and even “How many people are you going to be hugging today?” She added, “I’m looking at clothes come back. I’m like, ‘I can see the person’s face.’” Wrinkle testing was routine, white was off limits to avoid makeup stains and rubber soles were added to shoes to avoid any slips. Obama said, “I really thought about what I wanted to say with my fashion. I wanted to talk about inclusion, diversity and opening up opportunities.”

Obama said, “In fashion, there’s been a tendency for certain designers to feel like they own the first lady. So like anything else, that kind of attitude blocks out opportunities from other designers. So I thought about that.”

Her choice of a one-shoulder white embellished gown for the 2009 inaugural balls was not lost on Jason Wu. He said, “As an immigrant, you know, a Chinese American Canadian person, I’d never thought that option was available to be able to dress a first lady.”

Friedman explained, “She’s using their clothes to tell a story about what the Obama administration thought was important, right — American entrepreneurship, the American melting pot, the American dream.”

Rodriguez spoke of how meaningful it was for him, as the son of Cuban immigrants, to see Obama in one of his dresses at the 2012 Democratic National Convention.

Although sometimes people can get lost in their struggles, Obama said, “When folks are facing tough economic times, when jobs are scarce, when opportunities seem to be less, it’s easy to have somebody make you think it’s somebody else’s fault. But when we look around at truly who has built this country, it’s all of us. And all of us are Black, brown, Puerto Rican, Mexican, American, Italian, Irish, Haitian, come on. You know, that’s the story of America. Right. And it is the most true in fashion.”

Viewers also saw clips of Obama wearing a cardigan — a much-criticized choice — to greet Queen Elizabeth II in London in 2009, and then wearing a Jackie Kennedy-inspired white gown designed by Tom Ford for a 2011 state dinner at Buckingham Palace. There are plenty of images of her post-White House style including gold thigh-boots, long braids and edgier fashion choices. With frost-colored lipstick and a pale blue manicure, she wore a denim jacket with an oversized black floral brooch and cuffed jeans for the interview. Her hair stylist Ana Tu, and Jerry Radway, who does her braids, made cameos, as did her makeup artist Carl Ray. 

Asked about showing up in her natural hair after leaving the White House, she said, “Even if I didn’t do it for those eight years, I understood the importance of doing it at some point and signaling a message to young girls and to professionals out there, stay out of our hair. You know, we’re just trying to get to work and do it fast and efficiently. Don’t tell a Black woman how to wear her hair. How I wear my hair should be my choice.”

Telling Roberts how being in your 60s is probably the start of the last chapter of one’s life, which is something that she considered after her mother, Marian Robinson, died. Having always been someone, who said, “‘People don’t need to live forever. Don’t mourn for me. Death is part of life.’” Obama recalled how (near the end) she looked over and said, ‘Wow, that was fast.’ I said, ‘What do you mean?’ And she said, ‘Life.’”

Obama added, “I want to know that what I do is purposeful, meaningful to me. And that if it takes a lot of time, I know it. And I’ve made that investment intentionally.”

That approach has also been applied to her fashion choices. Obama said, “Look at the diversity, look at the, the faces of what is what it means to be an American. I was able to show the world the outstanding qualities of people who come from different places with different backgrounds, with different skin colors, with d from different genders. And sexual orientation excellence is not measured that way. And it is true in fashion and in law, and in journalism and in research. Let us not forget that.”

“That was the point, to find the best designers, to give them a stage to show the world how great they were. That’s what makes America great, right?” she said.