Reply To: Page title background

Hello,

You can change the image for the category header from Products >> Categories >> Edit category.

Screenshot for Clarification: https://gyazo.com/2b81ab837d066b1d0642ee902a4a3c95

And to change the navigation text try adding the following Custom CSS in the Custom CSS for Desktop area under Theme Settings >> Custom CSS.

.wd-nav[class*="wd-style-"]>li a {
    color: red;
}

Best Regards.