Setup your Project Background
You can set a project background for your screenshot set from the Background button in the top toolbar.
A project background can be a solid colour, gradient, your own uploaded image, preset image or Unsplash image. Panoramic backgrounds are useful when you want one background to flow across all of your screenshots.
You can also set a different background for an individual screenshot from the Background tab in the edit panel. Individual screenshot backgrounds sit on top of your project or panoramic background.
For step-by-step instructions, see How do I change the background?