Color shots are already available. Recently revealed: four equidistant, huge dark splotches around the planet’s equator: http://www.universetoday.com/121158/red-faced-pluto-full-of-surprises/
Almost as much fun as that belt around Iapetus, making that moon look like a walnut, or the speculation that Phobos might be hollow...
With little to go on, I’d guess that the 4 dark spots are shadows from massive vent-plumes pushing gas up into Pluto’s atmosphere.