  Parton shower event generators typically approximate evolution of QCD color
so that only contributions that are leading in the limit of an infinite number
of colors are retained. Our parton shower generator, Deductor, has used an
"LC+" approximation that is better, but still quite limited. In this paper, we
introduce a new scheme for color in which the approximations can be
systematically improved. That is, one can choose the theoretical accuracy
level, but the accuracy level that is practical is limited by the computer
resources available.
