Making a black and white (two coloured) background

For our app we need a background that is black on the left side and white on the right side.
How does one do that?

You have row function in the Layout and you can extend that box to match the hole page and in each box you can assign the background color or image that you want.

You would need to place a base container in your Page Layout with 100% width and height, respectively, in which everything else on the page is nested into. You would then create a simple image with the color schema you’ve described in some graphics software. You would then upload it as the container’s background and set the image to “Cover” in the Style tab for the container. If it doesn’t align perfectly, you can experiment with the background image’s dimensions and then reupload, or you can try formats other than Cover in the same Style tab.