MacOS – How to invert colors in Safari pages on macbook

Yes,

There is an extension for this called ZoomBySite. Here is a description of the software from it's website:

ZoomBySite is a Safari Extension that will automatically zoom each site to the zoom level of your last visit to the site. A site is defined by a unique domain name (so www.apple.com is considered different from store.apple.com and each could have its own unique zoom level).

It does this by intercepting the Zoom In and Zoom Out keyboard shortcuts [...]. It zooms the page in or out by the desired amount (see the Preferences section below) and also stores the zoom level for the site. As each page loads, it checks to see if there is a stored zoom level and sets it again for the current viewing. If you change the zoom level of a site, any other tabs or windows that are open to that site will also change their zoom level.

Unfortunately the range of extensions available for Safari is pretty limited, and no one has written such an extension at this point.

Also having written an extension or two for myself in the past, there is no way to access the tabs and colour them in any way, so it would not be possible.

It may be worth looking at another browser such as Google Chrome, or Firefox.