Hear me out:

Sport coats. (edit: and blazers)

Very light linen ones for hot days, which keep sun off your skin without really making you hotter. Cooler days, break out the wool.

All those extra pockets are wonderful. Grab some thin old mass-market genre paperbacks and discover why they made them that size :-)

They're like purses for men, that you can wear instead of carry, and that make you look better. Similar storage capacity to a fanny pack, I'd say. Maybe a little more.

I wear a short sleeve polyester t-shirt in black. I own a dozen of them, all identical, and wear them most days. My wife hates it.

The black is not good on very hot days. It’s surprising how much difference a light color makes. But, I can’t seem to keep light stuff clean.

I don’t know if I could stand my arms in a sport coat, but I guess it’s no different from a regular jacket in the winter.

Yes, my teenagers were shocked and appalled when they saw it, and made me promise I would only wear it while on the bike.