So that lady in red stirs up passion in men -- "dancing with me, cheek to cheek ... the beauty by my side," as the Chris DeBurgh song goes.
But how does her dress color affect the women around her? A recent study from the University of Rochester with collaborators from Trnava University in Slovakia and the Slovak Academy of Sciences say not so positively.
In fact, it makes them fiercely guard their man.
A study, published today in the Personality and Social Psychology Bulletin, finds that female onlookers, when shown photos of another woman wearing red, jumped to the conclusion that she would be a sexual threat.
In the study, researchers did three experiments, showing female subjects photos of other women dressed in red and in white dresses, and then in red versus green shirts. They hypothesized that the color red would be a "sexual receptivity cue and that this perception would be accompanied by rival derogation and intentions to mate-guard," according to the study.
"We tend to take color for granted," said the study's lead author Adam Pazda, a graduate student from the University of Rochester. "It's not just a pretty thing in our environment that adds to the aesthetic experience in the world. Behind the scenes, it can affect us psychologically in the way we perceive others or ourselves."
"It helps us make sense of other people's behavior when women are out in red and they are getting the cold shoulder from other women," he told ABC News. "Maybe they are giving off the perception of a romantic competitor."
Pazda said the study "essentially replicated" a 2008 study on male subjects that found men perceive the color red on a woman to be a "signal of sexual receptivity."
Researchers did three experiments on several hundred women, using a photo of a woman in a dress that was Photoshopped in white and red, then an image of a woman in a green versus a red shirt. In all photos, the face was blurred out.
"Everything was identical, except for the color," Pazda said.
In the first, they asked the study participants, "How interested in sex is she?" and "How seductive is she?" More women said the woman in the red dress was "more open to sexual encounters" than the one in white. They responded along a "sliding scale" from "No, not at all" to "Yes, definitely."
In the second experiment, researchers wanted to see if women would "derogate" or make negative comments about the woman in red.
"We asked about two subjects, sexual fidelity and how faithful a woman is, and their financial resources -- how much money they had and if they drive a nice car," Pazda said.
Participants again made more derogatory comments toward the woman in the red dress.
In the third part of the study, the color was switched from white to green, to rule out perceptions about virginity and purity normally associated with the color white. The woman in the photo was wearing a shirt, not a dress. Researchers also only questioned study participants who were currently involved in romantic relationships.
"We asked how likely they would be to introduce their boyfriend, and these women were reluctant to leave a man alone with a woman in a red shirt," he said.
But several women interviewed by ABC News who were not study subjects drew more positive conclusions as to how the color red is perceived.
Amy Wolfe, 35, of Berkshire, Massachusetts, says that for her, red suggests "confidence."
Hillary Mains, 32, from Pepperell, Massachusetts, agrees that "red definitely evokes someone who wants to be seen -- confidence and pride."
"Va va va voom," is the phrase that 54-year-old New Yorker Amy Spiegel uses.
"There's lots of science about red as a sexual lure in primates and human beings, which is doubtless where the 'scarlet' woman comes from and Bette Davis wearing red as a virgin in 'Jezebel,'" said Peg Streep, an author who writes about psychological research.
"In the movie 'Pretty Woman,' they played on that because Julia Roberts is in red when she's a 'lady' at the opera, not a whore."
"I think red signals confidence and, yes, the statement 'I can play this game' and 'look at me,'" she said. "The older I get, the more red I wear, meaning 'don't count me out!'"
But researcher Pazda said the study results can "help us learn about ourselves."
"Men think red is attractive and sexually receptive," he said. "You might think twice about wearing red to send off the wrong vibes. ... If you are wearing red out and about, you might be perceived negatively by other women. It won't happen in every situation, but be aware of the signals to other women and men that you're interested in sex."