I'm trying to make an entire section of my website have a black background with red text. I can get it all setup in the design tab > customizations. The problem is I need a way to apply this to every page I add to this section automatically or else it's a tremendous amount of extra work.

Every section I add to this page is in the form of a page type that I created for it, but in page types you can only add blocks to the default output, it doesn't let you setup a custom design theme for the page type, only live pages and drafts.

Does anyone have any work arounds for this problem? I'm planning on adding potentially hundreds of hand written pages to this section and if I have to go to design > themes > customizations and go grab color codes from a notepad document and paste them into the appropriate places and change the text sizes for some of the headings every single time I make a new page it's going to add up to an absurd amount of work and time in the long term.

Please tell me someone has encountered this before and has some quick fix or easy solution for this.