0\farcs2$, and the arc extends over a comparable distance, $\sim 1\farcs5$. The colors of the images of the core have a mean of $R-I = 2.2 \pm 0.1$ mag, and differ from the mean $R-I = 1.3 \pm 0.3$ mag color for the arc. Thus, if the arc and the core sources had the same color, the measured color differences would argue in favor of reddening in the host galaxy of the QSO, instead of in the lens galaxy. However, it is possible, for example, that the arc is a distorted view of an HII region with no physical association with the QSO core, and with a bluer color. If the lens galaxy G were at $z = 0.5$, the “most likely” value estimated by Kochanek (1992), then extinction in G could account qualitatively for the optical color differences among A1, A2, B and C, as well as for the IR magnitudes and for the unusual line ratios found in this system (LEJT95). The color differences would arise from extinction in G that is sufficiently patchy to yield such differences on a length scale of $\sim 0\farcs4$, the smallest separation between the images of the core. We find no variation 