Improving field visibility for keyboard shortcut in dark theme

Improving field visibility for keyboard shortcut in dark theme.

**At the moment**
<img width="561" alt="Alt Dunkel" src="https://user-images.githubusercontent.com/62497891/117359004-20f35c00-aeb7-11eb-9bae-61d7cb48e997.png">

**Example**
<img width="561" alt="New Dunkel" src="https://user-images.githubusercontent.com/62497891/117359239-6a43ab80-aeb7-11eb-8b24-2b1b936dd4fa.png">
