Here I am in Albuquerque, staring out the window to the west. This is a dry desert clime, a clear cold day, slightly before 8 am. There are scattered clouds in the sky -- a sky we would call "blue" by reflex. But as I look to the west, the sky at the horizon isn't blue at all. Not even close.

Right at the horizon -- which by the way is analogous to the region of sky generally shown on Mars images -- the sky is a pearly pale bluish/ruddy/white. Artists have known and loved the effect for generations. There is a definite ruddy cast to the sky as my eye rises from the horizon, but it's not red or even pink. The overall impression is a slightly off-white color -- with bluish, pinkish and yellowish tints.

Higher above the horizon, the sky becomes bluer, but it is still very pale, except almost overhead, where the blue is very strong.

Here in New Mexico, the air is often laden with dust, and when it is, the sky near the horizon can be quite yellow or brown (there isn't much red dust in this area). But above the dust layer, the typical white/bluish/pinkish/yellowish colors are typical.

Nearly everywhere on Earth, the sky near the horizon is usually whitish, not blue. And it's almost always very pale.

Would an analogous effect appear on Mars? Why not?

I don't know what the "correct" colors of Mars surface and its sky are, but there is reason to disbelieve many of the widely circulated NASA/JPL images going back decades. Some of the color images being circulated from the Spirit and Opportunity landers and the Mars Express Orbiter deserve criticism for their apparent bogosity. "Bogus" in the sense that some may be Photoshopped black and white images, unrelated to color filters used; some may be grossly exaggerated color images utilizing color filter images, and some may be grossly inaccurate color images utilizing IR rather than visual wavelengths.

As has been pointed out, this sort of thing goes on all the time, generally without acknowledgement by those who do it. Or contrariwise, multi-hundred page arguments are submitted justifying the inaccuracies and exaggerations.

This has gone on for decades.

And no doubt will continue!

Cheers, BRFelix