While shoes often are the last thing to go on in the morning and the first to come off when you go home, anyone who pays attention to the almost $42 billion footwear industry knows that shoes are anything but an afterthought.

ShoeMall.com, an online retailer, conducted a "census" to find out the demographics of the 1.4 billion pairs of shoes sold in the U.S. last year.

Overall, black basics rule.

Among the 560 women ages 18 to 54 surveyed by Greenfield Online last month, seven out of 10 reported having three or more pairs of black shoes in their closets. Yet, 26 percent responded they "could use a few more."

Many of the black shoes already out there tap into a current fashion trend -- patent leather. Twenty-nine percent reported owning such shiny shoes.

As for other colors, brown is popular, owned by 77 percent. Other top colors were red, metallics, patterns or prints, pink and yellow.

A healthy majority, 64 percent, own pumps, and 7 percent of women earning annual salaries of $100,000 or more own 10 or more pairs of pumps.

However, American women also like comfort and casual style.

Nearly every woman (94 percent) reported owning a pair of sneakers -- and half had three or more pairs -- while 66 percent owned flip-flops. Women age 24 and younger seem to be the biggest fans, with 84 percent fessing up to flip-flops.

Flip-flops, though, largely have run their course as a fashion item and soon might return to being the beachwear item they were originally intended as.

"I'm not surprised at some of the findings -- that there are an overwhelming amount of practical shoes, black shoes and brown shoes in their closets," said Beverly Gordon, the chairwoman of the environment, textiles and design department at University of Wisconsin-Madison. She helped ShoeMall interpret the results.

She sees colorful shoes as a growing trend because they offer "playfulness, energy and relief from the difficulties of our lives."

As for the wedges, platforms and peep-toes that have garnered a lot of buzz for spring, fewer than one-third of women already have those styles. Flats are another big style story for the season, but they're a trend that has already been embraced, with 74 percent owning at least a pair.

All those shoes can cost money, buy generally, women aren't spending it all in the same place: The average cost of a pair of women's shoes is $40, according to the survey, and only 1 percent said they had spent more than $500 on a pair.