  The radial velocity technique is currently used to classify transiting
objects. While capable of identifying grazing binary eclipses, this technique
cannot reliably identify blends, a chance overlap of a faint background
eclipsing binary with an ordinary foreground star. Blends generally have no
observable radial velocity shifts, as the foreground star is brighter by
several magnitudes and therefore dominates the spectrum, but their combined
light can produce events that closely resemble those produced by transiting
exoplanets.
  The radial velocity technique takes advantage of the mass difference between
planets and stars to classify exoplanet candidates. However, the existence of
blends renders this difference an unreliable discriminator. Another difference
must therefore be utilized for this classification -- the physical size of the
transiting body. Due to the dependence of limb darkening on color, planets and
stars produce subtly different transit shapes. These differences can be
relatively weak, little more than 1/10th the transit depth. However, the
presence of even small color differences between the individual components of
the blend increases this difference. This paper will show that this color
difference is capable of discriminating between exoplanets and blends reliably,
theoretically capable of classifying even terrestrial-class transits, unlike
the radial velocity technique.
