
Hi, I am Paulo and I'd like to help.
The new tab page looks to be applying an overlay on top of the image, darkening it. This is by design regardless of the OS. Unfortunately, there's no permanent solution to disable or remove the overlay.
You can check ¡Firedog's answer from this thread:
https://answers.microsoft.com/en-us/microsofted...
There's no other way, but to submit feedback and hopefully they can give us the option to remove that. You can use the new tab page's link by clicking on the gear icon > scroll down at the bottom and you'll find the Feedback link. You may also click on the three dots > Help and feedback > Send feedback.