OK, they didn't use red pumps. They used red shirts. And this research may fit under the category of psychologists demonstrating what everyone already knows. But I was still pretty amused to see that Andrew Elliot and Daniel Niesta published an article called "Romantic Red: Red Enhances Men's Attraction to Women" in the Journal of Personality and Social Psychology (2008, vol 95:1150-1164). Note this is not a marginal journal, it is among the most prestigious journals in psychology.
In a series of five studies, starting with subjects looking at a picture of woman against red versus white backgrounds, the researchers found that heterosexual men were more attracted to a woman pictured against the red background. Other colors had no effect and the "romantic red" effect did not affect how female subjects rated the attractiveness of the woman in the picture. In another experiment, the researchers selected a picture of a moderately attractive woman from the website "hotornot.com" and used photoshop to produce two (otherwise identical) pictures of her in a red and a blue blouse.
The sample strikes me as mighty small in this final study (12 in the red condition, 11 in the blue condition), but the effects were large. The young men who viewed the woman in red blouse reported that they found her more attractive in general, would be more likely to ask her on a date, found her more sexually desirable, and would spend more money on a date with her compared to the same woman woman in blue. This research also found that color had no effect effect on men's attributions of a woman's kindness, likeability, or intelligence. And it showed that the subjects in the study were unaware how color was affecting their preferences.
Here is part of the the researchers' justification for their "red-sex" hypothesis:
"As such, it is likely that women, like other female primates, display red more often and more prominently when nearing ovulation. We also think it reasonable to posit that men, like their more primitive male relatives, are predisposed to interpret a display of red by a female conspecific as a sexual signal and to respond accordingly." (page 1151).
We human beings sure are weird, huh?