A little known fact about Bento is you can update the logo found on the unsubscribe page as well as the brand colours.
To do so, simply:
1️⃣ Click the settings icon (⚙️) in the menu and navigate to Environment Variables.
2️⃣ Add a variable called brand_logo with a URL to your image.
3️⃣ Add a variable called brand_colour with a HEX value (#999).
After you've added both, go click on an unsubscribe URL and check that it's all working correctly.