Let's start by setting it up: 

1. Go to the website where you want to update the AI Content Engine.

2. Click on Pages in the left sidebar and select any web page.

3. Click the Design button in the top navigation in the editor.

4. Adjust the page design settings to match your branding.

5. Click on the Set as Website Theme button.

6. Choose the option that best suits your needs.

7. Click the Apply Theme button.

Once you've set up the global theme, you can always change it in website settings:

1. Go to the website where you want to update the AI Content Engine.

2. Click on Settings in the left sidebar.

3. Select the General tab on the settings page.

4. Choose the Theme sub-tab.