How can I split the background color on the Enterprise theme header?

Topic summary

A user is attempting to customize the Enterprise theme header with a split background color scheme: navy for the top section (logo and search bar) and white for the navigation menu below.

Initial Solution Attempted:

  • Another user suggested adding custom CSS targeting .main-nav and .secondary-nav elements with white background and black text colors
  • This approach partially worked but left gaps—the menu blocks turned white but didn’t fill the entire row, and dropdown menus remained blue

Current Status:

  • The issue remains unresolved
  • A preview link has been shared showing the incomplete implementation
  • The user is seeking additional guidance on how to properly achieve the desired two-tone header effect with complete coverage
Summarized with AI on November 15. AI used: claude-sonnet-4-5-20250929.

Thank you - we had tried that earlier but we end up with the following - the menu blocks are white - but it doesn’t fill the row and the menu drop down is still blue.