In the treacherous world of romance fiction, a reader could always count on a few certainties:

Bodice-ripping covers of the latest releases would smolder alongside the incendiary tabloid headlines at the supermarket checkout.

The hero would be tall, dark and handsome.

The heroine would have the body of Cindy Crawford and the maturity of the Olsen twins.

Point of view? Feminine.

Ending? Happily ever after.

But now, even in the entrenched realm of romance that accounts for nearly half of all paperback sales, things are changing.

In August, Pinnacle Books introduced a line in which the storyteller's voice drops into the masculine register. Named after its first entry--"A Man's Touch," by Debra Falcon--the series will release a new title each quarter, unless readers clamor for more.

Then there's that heroine thing. Invariably, she was an 18-year-old virgin with cleavage you could get lost in. But two years ago Zebra Books debuted the To Love Again line--contemporary tales of love between heroines and heroes for whom the bloom of youth--if not the hormonal imperative--has long faded.

Starting with "To Love Again" and "The Time of Her Life," the publishing house produces two books a month about women who are divorced or widowed or have been supplanted by younger women. They deal with underachieving adult children, suffer breast cancer and doubt their ability ever again to engage in meaningful sexual relations.

And the men? While romance-novel heroes have always tended to be tall and handsome, until recently they were rarely very dark. Although people of color have popped up in romance novels--say, a Native American integrating a historical Western romance or an exotically good-looking stranger of mysterious but clearly mixed heritage--the featured players generally have been as white as a Des Moines housewife in January.

Last summer Pinnacle rewrote this rule as well, colorizing the genre with Arabesque, a line that publishes two books each month featuring multicultural characters and situations. So far, all have concerned African Americans, but Pinnacle plans to introduce Latino heroes and heroines next year, and Asian characters later.

The romantic fiction industry, it seems, finally recognizes that passion--nay, even true abiding love--is not limited to a homogenous population of young white naifs in which only women show emotion and only men take action.