Change Writer’s colour scheme
Libreoffice Writer opens with a white page and a grey background; any hyperlinks you add appear in blue; borders are grey; and page and column breaks are purple – but you can change these default colours.
Click the Tools tab, then click Options at the bottom. Expand the Libreoffice dropdown menu at the top left, then click Application Colors (see screenshot below). You’ll see a list of page elements with their default colours. Click the relevant dropdown menu, choose a colour from the palette, then click OK to confirm your changes.