Opacity Around Header Text


I am having the opposite problem to those I found in the forum.

My pictures are very crisp, but that makes the text hard to read. How can I add a darker overlay so the text pops more?


You can see the answer here https://athemes.com/forums/topic/how-to-set-floating-header-bar-to-always-display/

Thank you very much Awan. I truly appreciate your help!