Sweat Resistant Suit Options?

Hi everyone. My fiancé (M25) and I (F23) are getting married next August. I really want him to wear a light grey suit with a light blue tie. He thinks it looks great too, but brought up that he’s worried he’ll sweat through it and the pictures will look gross. I didn’t even think of that, but it’s a great point. We’re getting married outside (20 min ceremony), but we’re planning to take most of our pictures outside around 1:00 (which is around peak heat). We’re in MN and it gets to be in the 80s during the summer.

Any advice on how we can make this happen without sacrificing the color scheme? We’re going more casual, with bright & vibrant colors, so black/navy wouldn’t really fit what we’re envisioning. Thank you in advance!