The theme has link settings for each area, so you need to adjust them all. In this case, you now need to set the content area link color.
The wrapper setting is the global one. Then each area can either inherit it, or set its own to override it.
For the CSS, let us make a test with the WordPress custom CSS box found in
Customizing ▸ Custom CSS > Additional CSS – WP Setting
Paste the rule below in it and see if the content text turns red. If it does, then we have a working place for custom CSS
#wrapper #content {color: red !important;}
If it does not work, leave the rule in and post back