getting Red background in Safari

I'm getting a strange red background when I visit some pages using Safari. on Chrome the page is rendered in white normally.

I am not using any extensions and plugins.

How do I fix this bug?

Safari: Version 10.1.1 (12603.2.4) macOS: Sierra Version 10.12.5

Edit: I do not have the paint flashing feature turned on, I also noticed that this bug occurs on local images with a transparent background without any stylesheets (see image below).

I tried opening a local file image, and it opens normally on Chrome and Preview. However on safari, the images has a red background.

Solution 1:

I think this is a feature for web developers called "paint flashing".

Right-click on a blank bit of a page and select "Inspect Element", this will open the Web Inspector in Safari.

In the top-right corner of the Web Inspector there are a few icons. One looks like a paint brush. On your machine I bet it is selected.

Click it to turn it off.

Solution 2:

I'm encountering this bug in Catalina (10.15.2) in Safari (13.0.4) and Mail on my Macbook Pro (15" 2017). I've posted screenshots here: https://discussions.apple.com/thread/250979814?page=1

It definitely seems related to rendering, and can be partly improved by selecting things on the page/ in the email, but will often only be removed where the selection is present. I also see this red fill prior to the contents of a page rendering in a Safari window. I also see it in open email windows that were fine previously, but have to be re-rendered at some point.

I'm hesitant to reset Safari since that seems to not fix the issue. This problem seems relatively rare online, and I don't have paint flashing activated. Any other tips or ideas are welcome!