I also have the first all-color version, labeled, if I remember right, as "Episode 99," and the drop in quality is still apparent. The same audio problems are still there. It looks to me like they still used color footage and audio from "The Menagerie" with much crappier color footage and still-crappy audio rounding out the rest of it.I still own a secondhand video-store copy of the VHS "Cage" from twenty years ago. The audio during the color-to-B&W shift is horrendous. And the picture quality goes into the toilet as well. But for 1986/87 when this edit was pieced together for home video and without all the current methods of cleaning up and digitally remastering/fixing images and sound it was a pretty good job.
I think those videos must still be at my parents' house somewhere, unless they threw them out. (Unlikely -- my dad's a much bigger Trekker than I.)