[Theme: Heuman] Sidebar top color change without changing primary color

So basicly, I have this problem. I want to change the sidebar top color were it usually says follow to the same color as the sidebar. But if I change the primary color to the same color as the sidebar, a lot of other colors changes, for example the “send” button in the comments and it makes it invisible.

So basicly, I want to change the top dark grey sidebar color to be the same as the sidebar color under it, without changing primary color.

I’ve tried googling and googling, and this is the only issue I’ve had so far that I have not managed to figure out myself.

Any help is appreciated, and the website is. https://www.toledoslifestyle.se

Regards,

Chris.

Edit: I have a child theme that I’m using.