Prince's favorite color has been popping up indoors ever since Pantone crowned Ultra Violet, a rich purple, its Color of the Year for 2018.

Outside, purple is popular, too.

Katie Dubow is creative director for the Garden Media Group, which tracks trends in fashion, food and technology. They spotted the rising interest in purple produce — including açai berries, purple cauliflower, purple asparagus, purple corn and elderberries — in a 2017 Whole Foods trend report.

Purple food not only looks striking on a plate, but also is rich in antioxidants, believed to help lower blood pressure, fight cancer, slow the aging process and protect the heart. "Purple is the new color of health," Dubow says. "It's nature's Rx."

Nutritionists and celebrities have also driven the trend, using social media to urge people to eat more purple food, Dubow says.

Gardeners will want to grow their own purple produce, predicted the Garden Media Group, which suggested 11 relatively easy plants to try at home, including beets, berries, eggplant, purple cabbage, purple carrots and purple sweet potatoes.

Herbs with purple flowers, including lavender, catmint and rosemary, are also popular for beds, borders and pots. "Garden designers say their customers are requesting herbs in the landscape," Dubow says.

As for ornamental plants, purple blooms remain perennially popular, but now foliage is going to the dark side.

"There's a big interest in foliage, and plants with darker purple leaves add contrast to all the shades of green," says Scott Endres, co-owner of Tangletown Gardens. "They're a head-turner on a garden center bench or in a container." And gardeners who want to add purple have more options than ever, thanks to advances in breeding.

"Ten years ago, unusual plants were only for collectors," Endres says. "Now more growers are willing to take them on in mainstream collections."

Some of his favorite purple-leaved annuals include elephant ear in deep eggplant with chartreuse veining ("It's a perfect color combination"), Purple Heart setcreasea, as a filler in containers, and Persian Shield, which boasts striking metallic purple foliage.

The challenge when working with purple foliage is to use it in the right place and pair it with the right companion plants, Endres says. "Dark is not going to pop. It's a cooler color. It's better suited for the backyard where you can appreciate it up close," as opposed to in front where you're going for curb appeal.

Plant purple foliage with "something that grabs your eye," he says, such as orange or chartreuse. Or, if you're a football fan, pair purple with yellow — and create a Vikings homage.