The phrase "dark background" refers to the color or setting that is deep and not bright. It can be used to describe the environment or situation that lacks light or has a somber feeling. Full definition
The figures in her paintings are mostly black men and women, isolated against dark backgrounds. (artsy.net)
Yes, you can wear floral jeans too but opt for something with smaller - scaled floral prints preferably with dark background color. (creativefashionglee.com)
It wouldn't have worked with the contrasting light and dark background at the bottom and yet I desperately wanted to include that long quote from the climax of the book. (thebookdesigner.com)