Part of book now has red border on frames and pink fill

[Bernie5E0A]

I have a weird issue. I am just making some corrections to a book file. Now when I open the file all the frames in the first chapter appear with a red border and pink fill. This only happens on my desktop machine (Mac Studio) not my Mac Pro (M1) laptop.

I don't know if this will cause me problems, but I'm puzzled by what it is trying to indicate. Any ideas?

Example shown in attached image...

Thank you to anyone who can help me with this!

[Bernie5E0A]

Just to clarify - the red border and fill are not showing as such in the fill and line settings - they seem to be Indesign trying to flag something to me.

[Derek Cross]

Check to see if your images are defaulting to an applied Object Style.

[Geоrge · Accepted solution]

It looks like these frames are tagged:

https://helpx.adobe.com/in/indesign/using/tagging-content-xml.html

[Geоrge]

To hide the color-coding of tagged frames, choose View > Structure > Hide Tagged Frames.

[jmlevy]

I am quite sure that it is a tagged frame (View menu > Structure > Hide tagged frames)

You can check and remove the tags (if they are not useful) by going in the Window menu > Utilities > tags

Edit: @Geоrge was faster and published his answer while I was typing!

[Bernie5E0A]

Awesome, thanks everyone. Yes, it looks like that frame was tagged. I much have done it by accident as it's not a feature I even knew existed. I will now educate myself on what this actually does, but feel reassured it's not a problem or error.

Thank you!