[Adventure Plus] Transparent header

I have upgraded to the Adventure Plus Theme and am hoping someone can help as I am not getting any answers from the creator.

When I first installed the theme I had a very cool look with a transparent bar behind my text, however, it shortly changed back to the black marble look. I would like to get the transparent look back if I could. The site is still in development however feel free to check it out if you think you can help me.

https://www.highbraestravels.com

Many thanks in advance to anyone who can lend me some help.