I really wish I could use a dark theme but I feel like these feature just doesn't work. There's just something about the ones made so far that are so far off the nice feeling of something like Photoshop's dark themes. Maybe it's because the Construct 2 interface isn't affected and thus looks really inconsistent. All of the event sheet icons were designed to be on a light background so they don't like nice when changing the colors.
A dark theme in C2, and then a nice consistent dark theme in PS: