  A planetary microlensing signal is generally characterized by a short-term
perturbation to the standard single lensing light curve. A subset of
binary-source events can produce perturbations that mimic planetary signals,
thereby introducing an ambiguity between the planetary and binary-source
interpretations. In this paper, we present analysis of the microlensing event
MOA-2012-BLG-486, for which the light curve exhibits a short-lived
perturbation. Routine modeling not considering data taken in different
passbands yields a best-fit planetary model that is slightly preferred over the
best-fit binary-source model. However, when allowed for a change in the color
during the perturbation, we find that the binary-source model yields a
significantly better fit and thus the degeneracy is clearly resolved. This
event not only signifies the importance of considering various interpretations
of short-term anomalies, but also demonstrates the importance of multi-band
data for checking the possibility of false-positive planetary signals.
