Dark spots on Vesta
Dark spots on Vesta One of the more intriguing aspects of Vesta as seen by Dawn is the "dark material" found across its surface. In most places, dark material is associated with craters. In this photo, the dark material shows up in the ejecta around two large impact craters, but the relationship between the dark stuff and the crater is not obvious. The left crater is the 17-kilometer-diameter Fulvia. In some places the dark material seems to be associated with small secondary craters, but in other places there is no obvious origin. This photo consists of three high-resolution images taken on December 20, 2011, March 13, 2012 and April 17, 2012, colorized with a lower-resolution image taken on September 30, 2011. NASA / JPL / UCLA / MPS / DLR / IDA / Björn Jónsson

Here is the color image on its own:

Dark spots on Vesta (HAMO color image)
Dark spots on Vesta (HAMO color image) An approximately-true color view of some dark-spotted terrain on the surface of Vesta, obtained by Dawn on September 30, 2011. This is located near 27.8S, 152.6 or 302.6E (depending on the longitude convention).Image: NASA / JPL / UCLA / MPS / DLR / IDA / Björn Jónsson

And here is a detail view of some of the dark material:

Dark spots on Vesta (detail)
Dark spots on Vesta (detail) Image: NASA / JPL / UCLA / MPS / DLR / IDA / Björn Jónsson