  An extensive phenomenological study of the Drell-Yan (DY) process in $pp$
collisions at various energies is performed in the color dipole framework.
Besides previously studied $\gamma^*$ production we have also included the
$Z^0$ contribution relevant at large dilepton invariant masses. We investigate
the DY cross section differential in invariant mass, rapidity and transverse
momentum of the dilepton pair in $pp$ collisions at RHIC and LHC. We consider
three different phenomenological models for the dipole cross section and found
a reasonable agreement with the available data. As a further test of the color
dipole formalism, we also study the correlation function in azimuthal angle
between the dilepton pair and a forward pion $\Delta\phi$ for different
energies, dilepton rapidites and invariant masses. The characteristic
double-peak structure of the correlation function around $\Delta \phi\simeq
\pi$ found for very forward pions and low-mass dilepton pairs is sensitive to
the saturation effects and can be tested by future DY measurements in $pp$
collisions.
