[Feature request] Set a new tab background priority instead of choosing one choice

[RZHSSNZDH]

My choice for background is unsplash, but sometimes internet connection fails or I need to use the browser offline so the background can't be loaded and turns to black. It is also the problem of GIPHY. It would be better to set a priority for the background instead of choosing one choice. For example user can set priority below instead of choosing unsplash or GIPHY: 1- Unsplash 2- GIPHY 3- Colour gradient In this case, if item one has a problem, item two loads, and so on.