Reply To: Page Border and Black Title Bar

2. To change the header section black color.

.inner-main-title{
  background: #fff;
 }

.inner-main-title .entry-title, .inner-main-title .page-title {
    color: #000 !important;
}

3. To change the menu in to lowercase.

.main-navigation li {
    text-transform: lowercase;
}

Hope, the above provided CSS codes will help you to make the section as your need.

Thank you