Please share store URL and I will try to help you with that.
I just checked, there is a lot of weird stuff going on with navigation colors (both for pc and mobile). I can provide you long code to fix it for now but that will result in slow performance and incapability of customize from theme editor. So, I would recommend :-
1. Play around with color settings from theme editor, hopefully you can fix it.
2. If that doesn't work, you can hire a developer to fix it and make navigation colors customizable from theme editor.
If helpful then please Like and Accept Solution.
Do you need custom changes on store or want to boost speed ? Hire me.
Feel free to Contact me on email@example.com