[Andressa Furletti]

I was having the same problem and I was sure it had nothing to do with display settings. I didn’t have that problem before and I’ve been using the same computer, software version and display for at least 3 years. I found this on the Apple forum and it worked for me:

In FCP go to the menu Final Cut Pro > System Settings.
Click on the Playback Control Tab.
Set the Gamma Correction to Approximate.

Mine was set to accurate, I have no idea why. Maybe an update chaged the settings, I’m sure I didn’t mess with that. Anyway, now it works. I hope it works for you as well!

Best to all.