set / change page background color (in PDF)

hi

i create PDFs and really would need to color some pages (the chapters titles for example) with a different background color.
i couldn’t find anything.

do you think it’s possible?

i just checked the Scrivener Manual
and it has some pages (like the Philosophy) with a different page background color

but i couldn’t find anything in the Manuel source project that mark that page to have a different background!