In this VIS image, taken by the NASA - Mars Odyssey Orbiter on April, 24th, 2014, and during its 54.287th orbit around the Red Planet, we can see a very small portion of the Martian North Polar Region named Olympia Undae. If you compare this frame to other previous images of the same Region you will easily be able notice how uniform (as well as neatly shaped by the Dominant Wind) the Dunes are in this remote area of the Red Planet.
The white spots which are visible in several areas near, in between, and on top of the Dunes, could (and should) reasonably be evidence of Residual Water Ice and Frost.
Latitude (centered): 81,1656° North
Longitude (centered): 217,2460° East
This image (which is a crop taken from an Original Mars Odyssey Orbiter b/w and Map-Projected frame published on the NASA - Planetary Photojournal with the ID n. PIA 18540) has been additionally processed, magnified to aid the visibility of the details, contrast enhanced and sharpened, Gamma corrected and then colorized in Absolute Natural Colors (such as the colors that a human eye would actually perceive if someone were onboard the NASA - Mars Odyssey Orbiter and then looked down, towards the Surface of Mars), by using an original technique created - and, in time, dramatically improved - by the Lunar Explorer Italia Team.