  We evaluate the differences of HOMFLY-PT invariants for pairs of mutant knots
colored with representations of $SL(N)$, which are large enough to distinguish
between them. These mutant pairs include the pretzel mutants, which require at
least the representation, labeled by the Young diagram $[4,2]$. We discuss the
differential expansion for the differences, it is non-trivial in the case of
mutants, which have the non-zero defect. The most effective technical tool, in
this case, turns out to be the standard Reshetikhin-Turaev approach.
