It is a Light Red theme.

Light Red - Firefox Add-on
Light Red is a Firefox add-on that allows you to personalize your browsing experience with a beautiful Light Red theme. Enjoy a visually appealing interface while browsing the web.
Add-on stats
Manifest V2
Weekly download count: 2
Firefox on Android: No
Size: 7.95K
Email: pg*****@hotmail.com
Ranking
Other platforms
Not available on Chrome
Not available on Android
Not available on Edge
Add-on safety
Risk impact
Light Red does not require any sensitive permissions.
Risk impact analysis details
- Low This permission has no access or impact on the user's system or data, thus carrying no risk.
- Low ******* ****** ** *** ********* ********
Risk likelihood
Light Red has earned a fairly good reputation and likely can be trusted.
Risk likelihood analysis details
- High This extension has low user count. Unpopular extensions may not be stable or safe.
- Low **** ********* *** ******* **** **** * ****** **** ***** ******** *** **** ****** ** ** ****** *** *****
- Low **** ********* *** ***** **** **** * ****** **** ***** ********** *** **** ****** ** ** ****** *** *****
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