Blue and Red color shifted drastically

I have the Steam version, and something happened within the last couple of weeks so that the launcher, when launched, tells me that “You have unsaved changes – do you wish to save them?” If I select “no”, then the game launches normally and everything is fine. If I select “yes”, then the game launches with what appears to be a really odd color glitch: red and blue are about half a screen apart, making the game unplayable. Restarting the game does not help, I need to reboot the computer, then select “no” from the menu and then things are ok.
In steam, in the library under properties checking the validity of the game files tells me that it wants to fix one, and it does, but nothing happens.
Any tips?
thank you.

In the games list in your Library, right click on Borderlands 2.

Go to “Properties.”

Click Set “Launch Options.”

Type, “-nolauncher” and click “Okay.”

Click “Close.”

If the problem is still there, go back and delete the “-nolauncher” and click “Okay.” You may have to speak with someone with Gearbox Tech Support.

Have you been changing nvidia 3D settings recently?

I have not been changing any settings to my knowledge. I could not find where to enter “nolauncher”, sorry, I am not terribly computer-affinate.