No, I don't expect something like the color change to be documented here (unless that thing is incorrectly documented within python.org's current release trees).

I do expect that just as python.org's OSX releases document the recommended version of TclTk to use (e.g., https://www.python.org/download/mac/tcltk/) there should be equivalent documentation describing what version of TckTk is actualy compiled into the Windows releases here (e.g., 8.5.9 or 8.6.4 or such. (Note that Tkinter.TclVersion/TkVersion aren't sufficiently detailed to dynamically determine the exact in-built versions either).

Beyond that, it's up to the user to read more about that specified or recommended release in the external Tcl/Tk docs (except where such documentation is present in the doc trees on python.org).