Rust + light green sounds like excessive irrigation.

Been raining a lot in OH?

Preventing rust is fighting mother nature sometimes with her rains. The only prevention is to introduce new rust resistant cultivars into your lawn by over seeding or renovation.

During spring when it's cool, you can maintain a shorter lawn during spring rains to allow the grass to dry out sooner. Nitrogen also remedies rust. During heat, mowing short AND nitrogen can cause even more browning of the grass. All you can do now is wait for the sun and wind to dry your lawn.