Seeming like the same stuff and being the same are very differnt. Just try to find clear ptex. Like I said should not be too hard I have never struggled to find it. Most people buy black as they find clear to hard to get looking good.
They do sell clear P-Tex, BUT the black P-Tex is better since when heated, it melts better and becomes more liquid and fills the whole hole ! Then depending of the size of your filling, but for bigger holes it is much better to use a P-Tex gun because it heats better than a open flame and you can press it better !