It would be very interesting and very helpful a light/dark mode in Traktor, many djs need to see in a comfortably way the monitor of their own pc/laptop under direct sunlight, especially in summer seasons, during, for example, a boat party, beach party ecc...
It's very difficult, if you don't have a very powerful hardware, to see the main screen of this software when you are playing in a bad position under the sun, or in many other situations like clubs with strong lights.
So, I believe that it's not a bad idea.