I think that there is room for an intermediate position between Zombie84's and ImperialFighter's. On one hand the old DVD and LD home video releases were often red shifted and washed out. They also frequently had their contrast boosted.

On the other hand, remastered Blu-ray transfers (by which I mean true remasters, not DNR scrubbing of old ones) that attempt to recreate the way that prints originally looked often appear strikingly different in terms of colors, because the old transfers were inaccurate; however, as Zombie84 stated, recreating the original appearance of films is never completely accurate. It is possible that, even with the best intentions, those who restore films sometimes overcompensate in their attempts to restore how films originally looked. The blue-cyan shift that is increasingly seen on many Blu-rays can be excessive, in my opinion.

The tendency of certain directors to revise how their films look also has to be taken into account. I am not prepared to accept that every time a Blu-ray looks different from previous releases it is all down to ENR emulation or an attempt to restore the theatrical look. The Blu-ray-is-always-right attitude is just as extreme as the attitude of those who cannot accept that a look to which they have become accustomed is the only way to present a film.

EDIT: Like dark_jedi, I have not yet opened my set. From screenshots, I agree with msycamore that the Blu-rays look better than the last DVD releases in terms of color. I am concerned about the cropping too though. ImperialFighter, I will try to let you know about the colors on the theatrical cut of Alien after I watch my copy.