Facebook search bar on my iPad is using invisible ink, how do I change it back to black?

Hello Bryvic,

Welcome to the Apple Support Communities. From your post, it appears you want to change certain settings within an app. We'll point you to the right place.

See if Facebook has the settings you are looking for to do so: Where can I find my Facebook setting?

If you're still having issues, try troubleshooting the app itself even if it doesn't have the issues described in this link: If an app on your iPhone or iPad stops responding, closes unexpectedly, or won’t open

If you still see the same thing, reach out to Facebook directly: Facebook Help Center

Take care.