How to edit red color on this theme

Hello,

I am pretty new to working in WordPress, and have basic understanding of HTML and CSS. I haven’t delved too deep into my php files for this theme, and I’m not even sure if this is the right place to ask. But here we go:

Here is my website: http://ghostideas.com/

I am trying to figure out where/how to edit the theme’s base red color (behind the Ghost and in multiple places on the site.)

The theme is Cherry child theme: theme53265

I am assuming that this would be edit-able in the php files. However, I don’t know where to begin looking, what it would be called, or how to find it.

If anyone has any insight, it would be greatly appreciated. If this isn’t the right place to ask, where is? Haha. Thank you for your help.