Hi CharonY,
I am not concerned about the dog being cued as they are trained to follow the specific odor of the individual they are to find, although I appreciate that line of thought... Fluorescent would work. Having an odor, as long as it is not toxic is ok as well as the dog has to discern and work through thousands of smells anyways (grass, dirt, bugs, other humans, animals, trees, cars, perfumes, asphalt, etc etc etc) so one other one (again, as long as not toxic) isn't bad. But, and this is the key, having something that is both light enough to be carried some what by the wind, but dense enough to drop like 'odor' (the sticky part and the rafts) is what I am looking for..I think adding color would be easy - probably as simple as food coloring.. But finding an oil that can be 'carried' by a smoke bomb OR some other delivery (spraying in a mist has been mentioned but very problomatic as just the action of spraying is going to distort (more so) the action of 'normal' odor by the pressure in the release). That is why I thought something mixed with a smoke bomb would work.. and came to you all