Hi Maria. I am not sure which image you are referring to, but you can alter pretty much anything by writing custom CSS code.
I recommend using a plugin like Simple Custom CSS to save your CSS (https://wordpress.org/plugins/simple-custom-css/).
If you’re not familiar with how to use CSS inspector in Chrome, it’s super easy to use and will make finding the css classes that you’ll need when you want to change the design. Here’s a great in-depth article about this: https://www.html5rocks.com/en/tutorials/developertools/part1/
Hope this helps!