Re: slightly pink smoke for AF?
Red is known by psychologists and those that study psych (like myself) to be a color that attracts the eye more than any other. Also it is considered "more visible" meaning that at a lower concentration it will still be more recognizable than a different color.
As Juno said, it's the dominant color in the room so it makes sense that it would be the most visible in the smoke. The others are reflected but not as strongly.
Billy, support your claim. You have said the same thing twice without even elaborating. Why would the juice change the color at all? The juice is what is being smoked in the bowl along with the leaves so why would it dripping down the stem (and thus not getting smoked) changed the color?