re: Mars hemisphere
I could find no documentation to go with this photo as nice as it is. Your question mite relate to the black field that Mars appears in causing a varying color. I can relate to the question not answer it. But answer it we must!
So it would seem.
This photo here is remarkable, no doubt about. I like the fact that it shows detail like a gray that separates the dark area of the south from the salmon color. But the Moon seems too red.
Woodlock