Do you have any more photos?
Based on this one pic it's a little hard to be sure. But my first thought is yes, piebald. The areas of no pigment will appear yellow, this is expected. Piebald frogs have really varied patterns. I've seen some with almost 50:50 pigment/albino. Others have blotchy areas of pigment. Yours has a nice unique pattern.
My piebald fellow has spinal and limb deformities. His spine is twisted and his limbs on one side are shorter. Since he is twisted, he spins when he tries to swim and ends up floating in the plants at the top. He needs to be handfed, but other than that he does alright for himself.
Deformities are common with piebalds. If yours seems healthy so far then it should be fine. Congrats on the rare find!