  We calculate finite-$N_\mathrm{c}$ corrections to the next-to-leading order
(NLO) Balitsky-Kovchegov (BK) equation. We find analytical expressions for the
necessary correlators of six Wilson lines in terms of the two-point function
using the Gaussian approximation. In a suitable basis, the problem reduces from
the diagonalization of a six-by-six matrix to the diagonalization of a
three-by-three matrix, which can easily be done analytically. We study
numerically the effects of these finite-$N_\mathrm{c}$ corrections on the NLO
BK equation. In general, we find that the finite-$N_\mathrm{c}$ corrections are
smaller than the expected $1/N_\mathrm{c}^2 \sim 10\%$. The corrections may be
large for individual correlators, but have less of an influence on the shape of
the amplitude as a function of the dipole size. They have an even smaller
effect on the evolution speed as a function of rapidity.
