OOXML documents are technically one endless page, thus changing a color of individual page is difficult to implement for compatibility reasons.

Easiest workaround for that case is to use a shape. Basically, you need to create a rectangle share from Insert > Shape > Rectangle, then draw a shape over the page you want to change color for and change Wrapping style of that shape to Behind the text. Visually it would look like that page color, you can do that for every individual page.

With that workaround, I am closing the suggestion as Invalid.

Unfortunately, I am not familiar with a program for working with documents that allows you to change the color of individual pages.

Are you familiar with a document processor that allows changing the color of separate pages? Can you share the name or a link to its documentation that describes the process?