Menu Items' Background Colors

Hi! I’m using the stock Simone with a child theme. I’ve changed the main navigation’s background color to orange in my child theme. I want the rest of it to stay the same because this creates good contrast. But some menu items seem to be behaving differently than others.

My menus are dropdowns containing post categories, pages, and external links. The external links and the pages have dark backgrounds when you are on the corresponding page (example: if you go to the Computer Access page, the Computer Access menu item shows as dark with white text, seen here http://imgur.com/C16Cued). Post categories have a white background, like this: http://imgur.com/wRM9DwN

I’d like to make all menu items have the same dark background, but I’m not sure what variable is controlling that. I thought it was .current_menu_item but changing that value doesn’t seem to do anything. I’m guessing there’s a variable for pages and a different one for posts, but I can’t seem to find it with devtools like inspect element.

I’m sorry I can’t link to the website, it isn’t live right now, just local. I’d be happy to show screencaps of it or maybe make a gif or show my CSS in gist, etc.

Any advice would be hugely appreciated, thanks!