[Suggestion] Dark Theme Window

[TheWhiteWolves]

It would be good if you could change the colouring of the Regex Tester Window to follow the same colourings of the dark theme if that is what you have selected (like myself and many people do).

I currently have the window docked on the left side of my window and it would be good for it to be the right colour when I switch to it.

[sharomank]

Maybe, anybody would like to doing this feature? :)