  We report on a BVRcIc survey of field W Ursae Majoris binary stars and
present accurate colors for 606 systems that have been observed on at least
three photometric nights from a robotic observatory in southern Arizona.
Comparison with earlier photometry for a subset of the systems shows good
agreement. We investigate two independent methods of determining the
interstellar reddening, although both have limitations that can render them
less effective than desired. A subset of 101 systems shows good agreement
between the two reddening methods.
