Not so silly!
Undoubtedly the immediate area surrounding the monitor where you are grading, affects your perception of colour and relative brightness. Necessarily the window of the application should follow the same rules.
In the old days of CRTs, the grading room was necessarily very dark and the surround black. This compensated for the relative lack of brightness of a CRT.
However today with good RGB LCD or plasma screens which are very much brighter, a dark room with a black surround is much too dark. Many would argue for low ambient daylight (no direct light) and a neutral gray surround to the monitor. Thus a 20-40% neutral gray for app windows is also optimal.
Video is today little different from photography in this regard. Coincidentally to your question, I am about to add a segment to
Camera To Print and Screen on exactly this topic. I should have it available this weekend