# <Inbox /> Updates - v3.9.1 - Novu Changelog > Novu changelog: <Inbox /> Updates - v3.9.1. Learn about the latest updates, features, and improvements to the Novu notification infrastructure platform. Canonical: https://novu.co/changelog/lessinbox-greater-updates-v391/ Markdown: https://novu.co/changelog/lessinbox-greater-updates-v391.md Last updated: 2025-08-31T22:03:00.000Z Apply custom styling using appearance key callbacks based on your app data - bell icons change color by severity levels, customize notification appearance with payload data, and show/hide preferences by user role. Published: 2025-08-31T22:03:00.000Z Categories: @novu/js, @novu/react, @novu/nextjs #### Dynamic Inbox Styling with Appearance key Callbacks Previously you could only apply static strings to the appearance keys of the inbox, now for selected keys dynamic styling can be applied based on the key context. For example: notification count, notification data, etc... [Learn more]() #### **Introducing notification severity** Notification severity is now represented on the Inbox styles, the bell icon will change color and the notification item will be highlighted with the given color. If you have unread messages with `medium` severity, the bell shows **orange**. Add messages with `high` severity, and it switches to **red**; otherwise, it remains gray. [Learn More]() ### Enhanced Inbox Features #### **New render props** New render props are introduced for `renderAvatar` and `renderDefualtActions` so you can now render custom react elements without re-creating the whole Notification Item. [Learn more]()