Weinberg soft photon theorem and its expansion on nonabelian case

Question

Weinberg soft photon theorem states that the only way to construct Lorentz-covariant theory of interaction of photons with the other particles by inversed square law is to introduce gauge invariant interaction. Does this theorem hold for nonabelian extensions? I.e., for Lorentz covariant theory of interaction of gluons with matter we need to introduce nonabelian gauge symmetry of interaction term.

Comments

Probably yes. Weinberg's argument shows that coupling must be to a conserved current, which should leave no other possibilities. I think this has been checked in the causal approach to QFT where the gauge group appears as a consequence of the interaction structure rather than as input. See the true ghost story of Scharf.