Wow, Mail email list color is neon green! Need fixed!

Ok I don't know what I just did but the background color of the email list is a neon green! I have no idea how to fix it. Here is a screenshot... That one email is not highlighted. When I click on it the highlight color is a gray color.

How do I fix it?? I've been through the settings, nothing is showing up as green. I checked Format>Show Colors but that doesn't seem to change anything. I checked the system preferences and nothing is green. I'm so confused as to what I did. If anyone here knows how to change that, please let me know..

System Preferences, General. Check to see which color you've got selected for highlighting.

It's a gray color. I deleted that message and non of the other emails I received had that green color. So I don't know what happened but it seems to be fixed.

Got any strange Rules going on?

Nope. The only rule I have is the default one that is for "News from Apple." So whatever happened is gone. And the new emails from this forum haven't had that issue so somehow it only affected that one email in the list.