Header Image
Replace the website title with an image (logo or a banner) and position the Page Header gadget on the page.
left-aligned / centered

on your Page Header gadget.
To replace the website title with an image,
provide the URL of your picture or upload it from the computer.
Select the image placement:
“Instead of title and description”
or “Behind title and description”
(serving as a text background image).
left-aligned
takes up half of the page width.

in the NAVBAR-LEFT section
To customize the parent container's background color,
go to "Advanced" -> "Backgrounds" -> "Navbar"
centered
stretches full width across the page.

in the HEADER section
To customize the parent container's background color,
go to "Advanced" -> "Backgrounds" -> "Full Header"