Using Voyager observations, we demonstrate that Triton's orbital light curve is strongly wavelength dependent, a characteristic which readily explains some of the apparent discrepancies among pre-Voyager telescopic measurements. Specifically, we find a light curve amplitude (peak to peak) that decreases systematically with increasing wavelength from about 0.08 magnitude (peak to peak) near 200 nm to less than 0.02 magnitude near 1000 nm. Peak brightness occurs near 90¿ orbital longitude (leading hemisphere). The brightness variation across this hemisphere is close to sinusoidal; the variation across the darker hemisphere is more complex. The decrease in light curve ampltiude with increasing wavelength appears to be due to a decrease in contrast among surface markings, rather than to atmospheric obscuration. Our model also explains the observed decrease in the ampltiude of Triton's light curve at visible wavelengths over the past decade, a decrease related to the current migration of the subsolar latitude toward the south pole: we predict that this trend will contine into the 1990s. ¿American Geophysical Union 1991