This is related to #NIP89
And the solution I found to add/remove #recomendedApps goes like this...
1. Go to nostrapp.link
2. Log in
3. Go to your profile
4. Select used #apps
5. Find if the highlighter is on your list
6. Click on it and switch off all the buttons
7. Now the highlighter should be gone from your #Amethyst client