I was replaying the early days with the colorblind scroll on, and I noticed that it was telling me a lot of gem colors that clearly weren't present on their equipment. At one point on day 2, it even falsely penalized me for using a ditz potion instead of lips, even though her staff had a yellow gem--but the scroll said both blue and yellow. I suspect it's rolling random secondary weapons for the adventurers and simply not displaying them, and that's confusing both the colorblind scroll and the early potion rules.