Recently, Google stopped highlighting on laptop which of your search results are ads. They said they did this to 'harmonise the layout', but it's more likely to just be about increasing their revenue by tricking you into clicking on ads...

Either way, you can take control by simply injecting your own local style sheet which tells Safari to add a background color to the search results that are ads.

That is what this extension does! It doesn't do anything else - no data is collected or sent anywhere.