It’s often said that the bridal industry is evergreen. While the term generally is taken to mean perennially enduring, the colorful reference might be more literal than metaphorical in 2013. Although traditional white diamond engagement rings still make up a majority of the bridal jewelry sold in the United States, stores are seeing a shift toward unusual designs—in fancy color diamonds, gemstones, and unconventional silhouettes—that pave the way for creative sales pitches.

At Marissa Collections in Naples, Fla., second marriages and a diverse ­clientele have allowed Jennifer McCurry to branch out in her engagement consultations. An interest in color has been steadily increasing, she says, whether in fancy color diamonds or vibrant gemstones. “Our buyers are often collectors, so they are educated and gravitate toward rare and unusual gems,” McCurry says. Every sales associate, referred to as a “stylist” at Marissa’s, has an accredited jewelry certificate from the Gemological Institute of America, helping customers feel comfortable and educated when stepping outside the traditional white diamond box.

McCurry has found particular success selling spinels, favored by professional gem dealers for their exceptional color range, rarity, hardness, and clarity. Red spinel rings, especially by Beverly Hills, Calif.–based designer Arunashi, have been a particular favorite among adventurous brides, says McCurry.

There is plenty of evidence to back up the sea change jewelers are seeing at retail. “During the past three years, other gemstone categories have taken away yet another half percent from [the diamond industry’s] market share,” Moti Ganz, president of the International Diamond Manufacturers Association, said in a recent statement. If the pace keeps up, he added, the diamond industry will lose, within the next two decades, more than 20 percent of its market share among consumers.

Matthew Rosenheim, president of Tiny Jewel Box in Washington, D.C., isn’t losing any sleep over the shift to edgier, more color-intensive bridal styles. “The absolute need for a traditional diamond in bridal seems to be changing,” he says, noting that budget constraints may partly explain the diamond trade’s diminishing market share. “Women are looking for unique designs, highlighted with colored diamonds in cognacs, champagnes, and yellows, or beautiful sapphires.” Black diamonds, too, are big sellers for both McCurry and Rosenheim, who is working on a 1.5 ct. rose-cut black diamond in a rose-gold setting for an excited groom-to-be.

Even the need for a solitaire engagement ring is being questioned, as both consumers and retailers are embracing a growing trend in engagement bands featuring mix-and-match colors. Tiny Jewel Box’s clients are drawn to designers with a handmade aesthetic, such as Alex Sepkus and Annie Fensterstock, who use detailed high-karat yellow gold alongside sapphires, rubies, and emeralds.

Some of McCurry’s biggest sellers are micro-pavé “engagement bands,” often in rose gold, dotted with black diamonds and colored stones that are offered as versatile, creative ways to say “I do.” According to McCurry, brides are able to get a mix-and-match, fashion-forward look for a fraction of the price while still maintaining a sense of individuality. “This is also great for continuing to engage that same customer,” she says, “as they usually come back to add more bands to their collection.”