I suppose that depends on your definition of clean. If it's eating foods in their most natural state, and avoiding processed foods, then I'd say no, most protein powders aren't "clean" because they are concentrates or isolates of proteins, and thus processed foods. Some may be more "clean" than others.
But who cares if X, Y or Z person says if it's "clean" or not? As Candi says, it's cleaner than protein bars (which are often not much more than glorified, protein-infused candy bars, some with some pretty nasty ingredients in, especiallyy as sweeteners). And who is going to give you a demerit if you eat a basically good diet, and have something that's maybe borderline "perfect"? (I'm not just addressing this commment to you, because I've seen quite a few questions like this wondering if X, Y or Z food is "clean," and I'm sometimes a bit mystified by it).
My favorite protein powder is "Vegan Complete," which is made from pea and rice proteins (high-quality plant proteins which, when combined, form a complete protein), as concentrates and isolates, plus vitamins, minerals, antioxidants, etc. Another protein powder I like, which is "cleaner" is "Vega," which is primarily hemp (a complete plant protein), pea protein, and flax, with fruit concentrates and other nutrients. I consider it "cleaner" because the protein sources are not concentrates or isolates. But it's also pricier.