Change header text color in Mobile

I have the navigation color set in my site's global header settings.  Unfortunately, with the background image I have on the mobile version of the site that text color is pretty much unreadable.  The desktop site is fine.  I know I could find another background image for mobile and use that.  What I'd like to do though is to make the navigation color different only on the mobile home page.  The rest of the mobile pages would be fine with the global setting.  How can I change that color only on the mobile home page?

Share you site url pls?