@Hikokujaku
As liekun pointed out in the first chapter, these are the scans of the official Manga volume, btnt however used the Manga Time Kirara MAX scans. In the Manga volume, the order of the chapters have usually been changed from when they appeared in the magazine, thus creating this difference. In conclusion, this is the real Vol. 7 Ch.2 and btnt's version of this chapter would be correctly referred as "Chapter 81".
Also, as you observed correctly, in the Manga volume all pages are in black/white with the exception of the first 5.