iPad Air screen shows red shadows around the screen edges

Ensure that you are reviewing the screenshot on a different device - and not the iPad where you see the issue.

If the issue is clearly visible when the screenshot is reviewed on a different device, perform a forced-restart of your iPad - as this will often clear an isolated software issue:

Force restart iPad (models with Face ID or with Touch ID in the top button)

If your iPad doesn’t have the Home button, do the following:

1. Press and quickly release the volume button nearest to the top button.
2. Press and quickly release the volume button farthest from the top button.
3. Press and hold the top button.
4. When the Apple logo appears, release the top button.

If the problem persists after performing the restart, it may be necessary to reset your iPad settings. While this reset will not cause any loss of data, as a precaution, it is always wise to ensure that you have a current iCloud or iTunes backup before performing the reset:

How to back up your iPhone, iPad, and iPod touch - Apple Support

When you are happy to proceed, you can perform the reset from iPad settings:

Settings > General > Transfer or Reset iPad > Reset > Reset All Settings

If the problem still doesn’t clear, the next step is to reset the iPad to factory settings:

Restore your iPhone, iPad, or iPod to factory settings - Apple Support

Otherwise, you would be best advised to seek assistance directly from Apple Support. You can contact the Support Team using the Support link at top-right or bottom-left of this page. Alternatively and perhaps easier, you can initiate and manage your support cases using the excellent Apple Support App. If not already installed on your iPad, the App can be downloaded from the App Store:

https://apps.apple.com/app/apple-support/id1130498044

You might also visit the Genius Bar at your local Apple Store or Apple Authorised Service Provider (AASP) - where the technicians will be able to test and assess your iPad - and you can explore your available options:

Genius Bar Reservation and Apple Support Options - Apple

You can easily determine if you have a hardware or software issue. A reliable method to confirm a screen or other hardware fault is to take a screenshot when the fault is evident - and then review the captured screenshot image on another device or screen.

When reviewed, if the artefact is not present in the screenshot image, then you have demonstrated that you potentially have a hardware fault that may require repair to resolve. By contrast, if the artefact is visible in the screenshot, the something other than hardware will be the cause.

Take a screenshot on your iPad – Apple Support

If the test suggests that you have a hardware fault, a visit to the Genius Bar at your local Apple Store is recommended - where the technicians will be able to fully test and assess your iPad. This will likely inform your next steps:

Genius Bar Reservation and Apple Support Options - Apple

iPad Repair – Official Apple Support

If the screenshot looks okay when reviewed on your Mac, then you should follow the advice already provided - and take your iPad to the Genius Bar at your local Apple Store or Apple Authorised Service Provider (AASP) - where the technicians will be able to test and assess your iPad. Here you can explore your available options for remedy:

Genius Bar Reservation and Apple Support Options - Apple