1. A system comprising: an input; and a color conversion subsystem coupled to the input to perform reversible color conversion on a plurality of vectors of color data, wherein the color conversion subsystem comprises a forward transform that performs color space conversion that is reversible in integer arithmetic, wherein the transform generates outputs Y.sub.rev, U.sub.rev and V.sub.rev according to the following equations ##EQU28## where R, G and B comprise components in each of the plurality of vectors, and at least one coder to code output results of the forward transform.