  The light-front wave function of a proton composed of three quarks and a
perturbative gluon is computed. This is then used to derive expressions for the
color charge density correlator $\langle\rho^a(\vec q_1)\, \rho^b(\vec
q_2)\rangle$ at ${\cal O}(g^4)$ due to the emission of a gluon by one of the
quarks in light-cone gauge. The correlator exhibits the soft and collinear
singularities. Albeit, we employ exact gluon emission and absorption vertices,
and hence the gluon is not required to carry very small light-cone momentum, or
to be collinear to the emitting quark.
  We verify that the correlator satisfies the Ward identity and that it is
independent of the renormalization scale, i.e. that ultraviolet divergences
cancel. Our expressions provide x-dependent initial conditions for
Balitsky-Kovchegov evolution of the C-even part of the dipole scattering matrix
to higher energies. That is, we determine the first non-trivial moment of the
color charge fluctuations which act as sources for soft color fields in the
proton with wavelengths greater than approximately $1/x \sim 10 - 100$.
