It'll always be a very good looking film ( A L I E N ) because of the 35mm and the quality of the cinematography - and the bluray obviously showcases elements of that to the best of any release so far... but I'd rather the teal and orange hadn't been boosted as it rather defeats the purpose of a definitive HD version. I don't believe that picture restoration should be lumbered with faddish trends. I noticed it most in Brett's demise sequence where the subtlety of colour I've always associated with the lighting in ALIEN is conspicuous in it's absence; but on looking again it's also very obvious in the Jockey chamber where the mist seems to have been almost obliterated by deepening the shadows and the spacesuit colours are extremely vibrant, the egg chamber is now so excessively blue that the layer of laser light is hardly a contrast at all (even the white Nottingham Lace in the egg is now blue); some scenes on the bridge of the Nostromo are also over saturated in blue/green; and the cocoon scene is so pushed into yellow that it is now almost looks just flatly and badly colourised.
I know 'teal and orange' is done to appeal, the opposites of the colour wheel and all that (and I know there is a campaign against it, there's a blog somewhere online highlighting the worst offenders) but it cheapens A L I E N, in places it's now as blue as Aliens. There was always a distinct difference in the colour palettes of both films so this colour 'correction' to a classic looks like hideous revisionism to me.
Not quite as bad as colourising Citizen Kane, but not far off.