Carolyn Nichols, an editor, writer and publisher of romance novels who influenced the genre’s evolutionary progression into stories that showed alluring heroines in greater positions of authority, who “stand up and fight back before they give in,” died Oct. 21 at her home in Portland, Ore. She was 78.

The cause was chronic obstructive pulmonary disease, said her son, Christopher Nichols.

Mrs. Nichols, who had grown up in Washington, moved to New York in the 1970s and launched her career in romance novels, a multibillion-dollar industry with an overwhelming female readership.

Under the pen names of Iona Charles and Carolyn McKnight, she began writing what is known as regency romance novels, often set in the early 18th century and populated by “barons and earls” who lived in castles and dressed and talked like nobility.

In the 1980s and 1990s, she was founding editor of two romance lines, Loveswept for Bantam books and Second Chance at Love for Berkley/Jove, which was aimed at an older readership that, as the name suggests, had already experienced at least one love affair.

As director of the Loveswept line of books, she published more than 900 titles, stories that featured heroines in heretofore unmentioned roles, such as construction job supervisors and bar owners. The titillating titles, however, remained. In the “Delaneys of Killaroo” series, Mrs. Nichols offered “Adelaide, the Enchantress,” “Matilda, the Adventuress” and “Sydney, the Temptress.”

“Gone are the days when the sweet, little trembling 18-year-old virgin in the typing pool got swept off her feet by the macho, conglomerate boss,” Mrs. Nichols told The Washington Post in 1985. The heroines, she said, were more likely to be “spunky, spicy” women ready to “stand up and fight back before they give in.”

“There’s no sadness in these books,” Mrs. Nichols added. “They’re about nice people who you’d really like to know. Everybody’s okay. There’s none of the sadness of real life.”

Researchers discovered that the Loveswept book line was targeting the same potential customers as Clairol, the Procter & Gamble subsidiary that specializes in hair care and coloring. So the companies entered into a joint cooperative agreement — “not advertising, but promotion,” insisted Mrs. Nichols. Some of the Loveswept books came with a coupon for 50 cents off the purchase of a Clairol color wash. But not just any color. It had to be same shade of hair as that of the heroine in the book.

So critical is hair color in the romance novel that Mrs. Nichols had taken to supplying artists for Bantam book covers with the Clairol color charts, according to the Los Angeles Times, and there were sometimes adjustments made in the book texts so that the hair of the characters matched certain Clairol styles.

On Mrs. Nichols’s watch, there was also a shift in the covers of romance novels, from the classic embrace of a macho, muscular man and a well-endowed woman to one that predominantly emphasized male sex appeal, targeting a mostly female readership

Carolyn Ione McKnight was born in Monroe, La., on July 29, 1939, and raised in Washington. She graduated from Wilson High School in 1957 and attended George Washington University. In the early days of public television, she was a writer for the Washington-area station WETA.

In 2001, Mrs. Nichols retired as a top executive at the New American Library.

Her marriage to Rodney W. Nichols ended in divorce. Survivors include her son, of Corvallis, Ore.