Highlight color stuck in submenus.

Created by: Lord-Kamina

Hello @vinceliuice; first, great work on this theme!

I'm not entirely sure whether what I'm reporting here is actually a bug on your side or not but here goes.

First, note that I'm using the gtk3 version; running it from actual MacOS 10.14 in order make Deluge 2.0 match the rest of the system. For the most part it works great, but I've noticed that if I highlight a submenu (or some other UI elements), the highlight gets stuck until I close and reopen the menu.

Here's some screens so it's clearer:

The same thing happens with both the light and dark versions; in fact, it's worse in the light version because as you can maybe see in the screens, only the background is stuck, while the font returns to appropriate color for a non-highlighted item, so in the light version that ends up displaying black text on that blue background and it's almost impossible to read.