Please consider setting your search edit border color, menu bottom color, and toolbar bottom color to the same toolbar background color.
This can be done from within Everything:
Copy and paste the following search into your Everything search box
/dark_search_edit_border_color=#00ff00
(where #00ff00 is the new color in hex #RRGGBB)
Press ENTER in your Everything search box.
If successful, dark_search_edit_border_color=#00ff00 is shown in the status bar for a few seconds.