How to change background on command block?

I’m creating posts on Github pages using a Jekyll theme. When I use three back ticks for a short code snippet it puts a box around the code. Instead of having the box I’d like to change the background color of the code. I’m new to Jekyll.
Here is a section of my _config.yml:

markdown: kramdown
highlighter: rouge

  • jekyll-sitemap
  • jekyll-paginate
  • jemoji

Any help would be appreciated!

This post in the forum was what I was looking for Text highlight in kramdown

<mark>code here</mark>