[Document size and artboards]

Hello! When you add additional artboards to your document, the background changes to a creepy light gray color that is very distracting. After much torment, I found how to change this inconvenient background setting. Perhaps the author of the question is no longer relevant, but it will be useful for someone else. You go to the initial area of the program (Setting) --> (User interface) --> (Artboard Background Gray Level). And in this setting you change the % to lower small values, then the background color will become darker.