The image shown of the closest Mars meteorite match to Bounce also has a light color:
Meteorite Linked to Rock at Meridiani
http://marsrovers.jpl.nasa.gov/gallery/press/opportunity/20040414a.html
Here is a detailed review of the mineralogy of EETA79001:
IX. EETA79001
Olivine-phyric Shergottite/Basaltic Shergottite, 7942 grams
http://www-curator.jsc.nasa.gov/curator/antmet/mmc/79001.pdf
It doesn't specifically say why this meteorite is so light-colored in it's interior. It is interesting though that like another famous Mars meteorite, carbonate was found in its interior:
ORIGIN OF "WHITE DRUSE" IN THE EETA79001 METEORITE
http://www-curator.jsc.nasa.gov/curator/antmet/marsmets/eeta79001/DruseWhite/DruseWhite.htm
But this carbonate is in small patches so I don't think it could be entirely the cause of the meteorites light color.
Figure 2 (Right). SEM image (10 µ m scale bar) of white druse (separate from that in Fig. 1) in EETA79001,325. Phases were identified by EDS (spectra not shown). Carbonate A is the same composition as that in Fig. 1.
Bob Clark
Space/Science » in reply to A book judged by its cover
Color of Bounce and EETA79001.