Hey there sanderdame,
Hope you’re well today!
You should be able to achieve this with some custom CSS. Please try adding the following CSS code in the style.css file of your child theme or add it in your site using the following plugin:
https://www.ads-software.com/plugins/simple-custom-css
.navbar-inverse {
background: rgba(0, 0, 0, 0.6);
}
Note that this is the original color of the header. Last numeric value (0.6) represents opacity where 0 is completely transparent and 1 is solid color. Replace it with what ever suits you the most. You can find more info about rbga colors here https://www.w3schools.com/cssref/css_colors_legal.asp.
Hope this helps ??
Best regards,
Bojan
