  We present a simple technique to estimate mass-to-light (M/L) ratios of
stellar populations based on two broadband photometry measurements, i.e. a
color-M/L relation. We apply the color-M/L relation to galaxy rotation curves,
using a large set of galaxies that span a great range in Hubble type,
luminosity and scale size and that have accurately measured HI and/or Halpha
rotation curves. Using the color-M/L relation, we construct stellar mass models
of the galaxies and derive the dark matter contribution to the rotation curves.
  We compare our dark matter rotation curves with adiabatically contracted
Navarro, Frenk, & White (1997, NFW hereafter) dark matter halos. We find that
before adiabatic contraction most high surface brightness galaxies and some low
surface brightness galaxies are well fit by a NFW dark matter profile. However,
after adiabatic contraction, most galaxies are poorly fit in the central few
kpc. The observed angular momentum distribution in the baryonic component is
poorly matched by LambdaCDM model predictions, indicating that the angular
momentum distribution is not conserved during the galaxy assembly process. We
find that in most galaxies the dark matter distribution can be derived by
scaling up the HI gas contribution. However, we find no consistent value for
the scaling factor among all the galaxies.
