Menu link background colour

Hi,

I’ve searched around, but can’t seem to find an answer that quite fits the problem I’m having.

In my main navigation menu, I have a bottom border line under active or hover links, which is fine, and… a background colour behind the active link, which… I want to change, and can’t seem to figure out how.

I’ve tried the customizer, but can’t seem to affect the background colour applied to menu items when active or hovered over.

Is it possible to set this background colour in css, and… make it 100% transparent on regular menu, and 0% transparent on sticky menu (as I’ve set text to change colour when menu is sticky)?

I’ve attached two screen captures. First is menu when not sticky… second is menu when sticky. I’m sure you’ll see the problem.

Any help appreciated!

Del.