Why is my background on my apple 13 black now?

Hello Robinmark,

We're a bit confused by your post, so we wanted to clarify a bit further. Are you saying the Home Screen wallpaper, or Lock Screen wallpapers show up black in color? Are you saying the iPhone screen is black in color when you're using it or try waking it?

If this is happening on the wallpaper, are you able to select another wallpaper and test it out? This covers changing your wallpaper: Change the wallpaper on your iPhone - Apple Support

Change the wallpaper on your iPhone

Want to change the wallpaper on your iPhone? You can choose a suggested wallpaper or one of your own photos.

Add a new wallpaper for your Lock Screen or Home Screen

1. In the Settings app, tap Wallpaper.

2. Tap Add New Wallpaper.

3. Tap Photos, People, or Photo Shuffle to choose your own photo. You can also select a wallpaper from a category like Weather & Astronomy, Emoji, Collections, or Color.

4. If you want, you can customize your wallpaper further. Then tap Add.

Change your wallpaper from the Lock Screen

1. Make sure that you previously set up Face ID on your iPhone. To change your wallpaper from the Lock Screen, Face ID must clearly see your eyes and the areas around them.

2. On the Lock Screen, touch and hold your Lock Screen to open your wallpaper gallery.

3. To select a wallpaper you already created, swipe left and right. To add a new wallpaper, tap the Add button .

From the Lock Screen wallpaper options, you can also tap the Focus button to link a Focus to a specific wallpaper, customize existing wallpapers, or swipe up on a wallpaper and tap to delete it.

If you can't use Face ID to change your Lock Screen, touch and hold your Lock Screen until the Customize button appears. If the Customize button doesn’t appear, touch and hold the Lock Screen again, then enter your passcode. 

Testing other wallpapers will help us to isolate that behavior further.

Let us know how it goes or the answers above for more help, take care.