PORT ST. LUCIE, Fla. — Mr. Met, a perpetually cheery mascot, is everywhere at Citi Field: on top of the dugouts, shooting T-shirts into the stands and hugging children. He is also on all manner of merchandise, like bobblehead dolls and sweatshirts.

For the first time, Mets players are also wearing Mr. Met on their caps. New Era, the official cap maker of Major League Baseball, has introduced a line of fitted caps for spring training that the company says are 40 percent lighter than traditional on-field caps and are designed to allow perspiration to evaporate faster, keeping players cooler.

The caps — one design for each team — also include new designs that replace previous spring training caps featuring more muted looks. Some of the new caps have little more than an extra splash of color. But several teams, including the Athletics, the Brewers, the Rays and the Reds, have bolder designs.

The Mets’ cap has an orange brim, a blue crown, an orange button on top and Mr. Met dashing to his left on the front. By baseball standards, the mix of colors and the mascot’s prominence amount to a fit of whimsy.