The red and green colors are from colors where atmospheric methane absorbs light, and shows a brighter (redder) northern hemisphere because of more high-altitude haze in the winter hemisphere. The blue is from an ultraviolet color and shows the high atmosphere and detached hazes.
Titan has a gigantic atmosphere, extending hundreds of kilometers above the surface. The sharp brightness variations on Titan's surface (and clouds near the south pole) come from an infrared filter where methane does not absorb light.
Comprised of images N1477321905 (MT3), 1985 (MT2), 2123 (UV3), and 2883 (CB3), 6.4 km/pixel image scale.
Courtesy Carolyn Porco, Cassini Imaging team, based at the Space Science Institute, Boulder, Colorado.