Hello,@Frank-Hager
Please follow these steps, To No colors on highlighting
Step 1: Go to settings -> Style Configurator.
Step 2: Select the language that Notepad++ has chosen, usually based on filename extension. You can also change this manually under the Language menu setting.
Step 3: Go through the Styles until you find the style that applied the highlighting. You can tell because the Background colour will match the highlighted color.
Step 4: Change the Background color to white.
I hope this information will be useful to you.
Thank you