I saw a fresh 70mm print of 2001 in the Seattle Cinerama last month. Two observations:
-Smilebox looks nothing like what one sees in the cinema, simply due to the differences between having the curve in the center of one's vision vs. in the peripheral.
-The color was, to my memory, close to the blu-ray (though it's hard to judge as the gamut of film is somewhat larger than REC709).