You might brighten them with steel wool, or an SOS pad. But that might be a mistake.

Carbon (non stainless steel) spokes are usually zinc plated or galvanized which protects them from the weather pretty effectively. If you clean and polish them you're removing their weather skin, and the rusting process will be accelerated.

You didn't say anything about the mechanical condition of the wheel. If it's OK, or if it's slightly out of true and can be aligned, forget the cosmetics, and ride these wheels until they give out. Then you'll be left with a difficult decision; replacing or rebuilding wheels is petty pricey amd may not be warranted on a bike like yours. The best option down the road might be to look for a yard sale bike of similar vintage, that has good wheels, and buy it for the wheels.

BTW- my oldest wheel still in use, is the rear wheel of my track bike, built with carbon spokes in 1968 or so, and ridden on the streets of NYC in all weather for years. The spokes show their age, and the weather damage, but the wheel is otherwise fine, and I'll keep using it until I can't any longer. I can't tell you haw often over the years people would comment, "you better rebuild the wheel ASAP. It'll rust through and collapse any day". So far "any day" has been decades in coming.