  We present the results of U-band and multi-color photometry during the 2001
superoutburst of WZ Sagittae. Our 10 nights of U-band photometry span the time
interval from HJD 2452118 to 2452197 while our multi-color observations range
from HJD 2452115 to 2452197. The U-band light curves are generally in agreement
with other datasets obtained during the superoutburst showing highly modulated
light early on, rebrightenings, and superhumps of similar shape and period
(except during the rebrightening peak). One of our multi-color datasets
fortuitously covers the first rebrightening and allows determination of the
accretion disk color temperature before, during, and after the event. It is
seen that the rebrightening is a change from a neutral disk (T~7000K) to an
ionized disk (T$\sim$10000K) and back again. We develop a simple limit cycle
model for this behavior which approximately predicts the semi-periodic
timescale observed for the rebrightenings. We discuss our results in relation
to accretion disk structure during superoutburst.
