  We put a new spin on Khovanov--Rozansky homology. That is, we equip
$\Lambda^n$-colored $\mathfrak{sl}_{2n}$ Khovanov--Rozansky homology with an
involution whose $\pm 1$-eigenspaces are link invariants. When $n=1,2,3$ (and
assuming technical conjectures for $n \geq 4$), we prove that this refined
invariant categorifies the spin-colored $\mathfrak{so}_{2n+1}$ quantum link
polynomial. Along the way, we partially develop the theory of quantum
$\mathfrak{so}_{2n+1}$ webs and make contact with $\iota$quantum groups.
