Okay, thanks. I'm guessing it's not easy because I tried out a ton of different "media search" plugins this weekend but none of them did the right thing.
If I find any though, I'll post back!
This is how I ended up doing this:
I added the following to my child theme's style.css. I'm using the Default effect everywhere, so I just changed the css for the default to not dim. This makes the change everywhere, which is fine with me: /* Prev…