LIKE A mortarboard-capped senior clutching his valedictory address, it’s graduation day for the ol’ khaki suit. With an array of dressier versions in stores this season, this staple of callow preppy spring style is all grown up and ready to take on a more professional agenda.

You may be thinking: Really? And with some justification. As inoffensive as khaki may be, sending it—in tailored suit form—into settings that are serious or formal can be a risky maneuver. Recall the widespread outrage when President Obama late last summer wore a tan suit to a news conference about the growing threat of ISIS. The casual air of the light suit, fretted critics, undermined the seriousness of the subject at hand; it was more appropriate, they argued, for downing mojitos at the country club than talking about terrorism.

Some of the best minds in menswear, however, respectfully and heartily disagree. Exhibit A: the spring runways, awash in distinctly sophisticated suits in khaki and other neutrals, from Hermès in Paris to Richard James in London to Todd Snyder in New York. Gieves & Hawkes’s creative director Jason Basmajian showed cotton-and-silk suits in an elegant taupe. “[Men] want to wear tailoring and it doesn’t always have to be a blue or gray suit. Everyone’s got that covered,” he said. “[Neutrals] look so fresh in the summer.”

Sid Mashburn, the amiable owner of the eponymous Atlanta store that prides itself on classic American tailoring, said men could easily wear the versatile look to an almost monotonous degree: “A khaki suit? That’s Monday, Tuesday, Wednesday, Thursday, Friday—morning, noon and night.” He currently stocks suits in khaki twill and a tan English wool fresco; he’ll soon have options in cotton poplin and a plain Italian wool weave. “We love it for the workplace,” he continued. “It’s a way to say ‘I’m dressed up but not fussed-up.’ ”

Kirk Miller, owner of bespoke suiting and ready-to-wear shop Miller’s Oath, also questions the rule that the lighter the suit, the more casual it is. “Nowadays, if you’re wearing a suit, you’ve already made [your look] more formal,” he said. However, Mr. Miller brings up an excellent point—not all khaki is created equal: “The difference between tan, khaki and stone is [considerable].” He prefers a richer tone. But once you’ve got the right color, he said, “it’s your perfect canvas.”