Alma 37:5

And now behold, if they are kept, they must retain their brightness; yea, and they will retain their brightness; yea, and also shall all the plates which do contain that which is Holy Writ.

If they are kept safe, they must stay bright. They will stay bright. All the plates that have Holy Scriptures will stay bright too.

If they’re kept, they’ll stay bright. They will stay bright. And so will all the other plates that contain sacred writings.