[rambambram]

What about a background (pattern) that has the noise already in it? I use https://bg.siteorigin.com/ often to create subtle backgrounds like the one on https://www.winkeljustitia.nl/

[fouronnes3]

I was thinking maybe there's a pure CSS way to do it? That seems to be inline with the style of the author's blog.

[rambambram]

Pure CSS would be nice indeed.

[ctnicholas]

I saved myself time by reusing a small noise image I'd used before, but you could do it with an SVG pretty easily!

https://grainy-gradients.vercel.app/