How can I change the grey background of the PDF preview in Google Chrome to black?

For example, on https://arxiv.org/pdf/1808.06394.pdf:

using this code in the console (and disabling the Dark Reader Google Chrome extension if it was enabled):

var cover = document.createElement("div");
let css = `
    position: fixed;
    pointer-events: none;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-color: white;
    mix-blend-mode: difference;
    z-index: 1;
`
cover.setAttribute("style", css);
document.body.appendChild(cover);

I can make the white background black:

However the background of the PDF preview in Google Chrome is still grey. Instead I would like something such as:

How can I change the grey background of the PDF preview in Google Chrome to black?

For example, on https://arxiv.org/pdf/1808.06394.pdf:

using this code in the console (and disabling the Dark Reader Google Chrome extension if it was enabled):

var cover = document.createElement("div");
let css = `
    position: fixed;
    pointer-events: none;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background-color: white;
    mix-blend-mode: difference;
    z-index: 1;
`
cover.setAttribute("style", css);
document.body.appendChild(cover);

I can make the white background black:

However, the background of the PDF preview in Google Chrome is still grey. Instead I would like something such as:

Following my asking How can I preview PDFs with Google Chrome in dark mode?, now asking about changing the design for the rest of the screen.