Author Christopher Nickens was watching a third season episode of “Project Runway,” when the designers were challenged to modernize a look for a fashion icon. The usual names were on the list of style icons, like Audrey Hepburn and Jackie Kennedy. Yet also included was Marilyn Monroe.

“I thought, ‘OK, if Marilyn Monroe is a fashion icon, why isn’t there a book written about her?’”

The thought led to “Marilyn in Fashion” (Running Press), a stylish collaboration with George Zeno, a fervent collector of Monroe images and memorabilia, that explores the movie star’s fashion aesthetic and its lasting impact. The book reveals the designers Monroe worked with, the elements of her style from head to toe, and her transition from brunette Norma Jeane Dougherty to blonde bombshell to sexy and elegant star; plus it’s chock full of tantalizing behind-the-seams tidbits that reveal the icon’s sartorial savvy and allure.

Nickens says he’s not a fashion guy. (“Once I found out how much she had a hand in her image, she worked with the designers and by the end she learned less was more, that was interesting to me.”) But when we spoke to him from his Los Angeles home, he offered much on Monroe and style.

Q: You quote Monroe from a 1953 article and she seems to really get the idea that you should wear clothes, that they shouldn’t wear you.

In many ways she was ahead of her time. One of the things that struck me about her that could stand for anyone is that you should wear what suits you. You want to be in style, but don’t become a slave to it.

Q: It’s pretty clear she thought her cleavage was an asset, but it seems she may have felt the same way about her shoulders.

She had a habit of pulling straps down. If she had a chance to do it, she did it. She knew she was a sex symbol, so she gave people that look of what she was already doing in the penthouse. Like her hair, it was a messy, subtle way of showing her sex appeal. When I say that people say it sounds so calculated, but I think it became very organic after a while.

Q: It’s interesting that as she got older, she had a specific color palette for special occasions – beige, black, white and flesh-colored/see-through. Is that a good rule for most of us?

It’s a good idea. We all have colors that flatter us more than others. You have to have the right skin tone for red, it’s based on your complexion. Darker skin tones can wear any color – look at (people from) Brazil with those costumes. But when you are light like Marilyn, it can wash you out. I don’t think in the five years before she died, she wore red unless it was for a movie costume. She was going toward elegance.

Q: She had three, maybe four iconic dresses – the “Happy Birthday, Mr. President” dress, the “diamonds are a girl’s best friend” dress, the “subway” dress, and maybe the gold pleated one. How do you rank them in style importance?

One of the designers I spoke to for the book told me this story about how she designed a dress for a class she was teaching; she uses African and Far Eastern influences. One of her students said “that looks like the dress Marilyn wore over the subway.” And it did. She didn’t even realize that. When a dress is that iconic, it sort of worms its way into your consciousness. I think the subway dress is the most famous dress ever, except unfortunately, the dress Jackie (Kennedy) wore when her husband was killed.

Johnson Martin: 919-829-4751; twitter.com/amajomartin