If was definitely water gel. I examined it thoroughly. The gel would be whatever color the liquid was that it absorbed, you have seen clear since it absorbed water. If on the other hand it were to draw fluid from the digestive tract... There is also the fact that they ( the frogs ) have been eating primarily fruit flies, so they have red tinted poo, Totally freaked me out the first time I saw it. Anyway, that could account for the color.