Hi, Leo.
I’m not sure why you cannot see the code. I can see it when I go into additional css and view source page.
Here is a link to screenshots: https://drive.google.com/open?id=1WQ0qY2sM0LqhKMXqFF-WY4cYFtF5bWul
I also went to Colours > Content > H2 and changed it to #222 and nothing happened. On the homepage, the post title is still in my accent colour and not the 222 I set it to.
I did notice that before I changed H2 in the customizer it was set to inherit (RRGGBB).
Link to demo site: efc21c12.ngrok.io
Thank you!