Around sunset and sunrise the Martian sky is pinkish-red in color, but in the vicinity of the setting sun or rising sun it is blue. This is the exact opposite of the situation on Earth.
In case you can't read the captions
Place: Earth > France > Marseille
Date: 18th May, 2012
Camera EOS 400D, 18 - 200mm
Place: > Mars > Elysium Planitia > Gale Crater
Date: 15th April, 2015
NASA / JPL / Caltech / MSSS / Damia Bouic
Pretty cool how the same man, a member of The Plantary Society, took both photographs.
And, if you want a chuckle, go to the NASA site and click on the link which reads 'not fully understood'. Tell me these guys don't have a sense of humor :)