In its latest release, Exacq added an option for a dark/high contrast UI, here:
I was happy about this because I find it much easier on my eyes. Milestone has had this option in the Smart Client for some time, and Genetec's Security Desk and Config Tool are both dark by default.
Question is: how much does this matter? Have you ever had a question from a customer about a light or dark UI or one or the other being hard to view for extended periods?