So the question is, does it work as advertised? And the answer is unequivocally yes--like magic. But it's important to understand, as Cabela's clearly states in the promotional materials, that "body heat, sunlight, moisture, and wind can affect the color-change process." With a constant outside temp of 52, for example, I moved mine from the shade to the sun and the brown colors turned green. On the other hand, I couldn't work up enough "body heat" to affect the process. With my Zonz hoodie on, did enough calisthenics (Damn I hate calisthenics!) to work up a good sweat, but it didn't turn the browns green.