I found the script to use in code injections for turning your whole site to dar-mode here: https://ghost.org/help/dark-mode-casper-theme/. This worked in turning my whole site to dark mode.
However, I just want to turn one of my pages dark and not all of them. I tried posting the same script in the page’s code injection header and the color did not change. Anyone know how to do this? I am running a custom version of Casper 4.0. I customized it to create a home page separate from my blog.