always remember: blu-ray is capable to hold a higher color spectrum then dvd or ld was able to do. so using a ld or even a dvd for reference might result in a wrong color display altogether.
i also not recommend to do color correction purely by eye, unless you
- have approved monitors for color correction, which are also properly calibrated
- have high knowledge of color correction using scopes
- know what the original intended look of the movie was
point 3 will be very had to fill, since none of has ever spoken to the directors to the extend a colorist would've or has access to the notes done during the color correction process.
the final results may look good, but also may not represent what was originally intended. a good example were i have mixed feelings about the result is andrea's the thing color correction. while it looks pretty good, i don't think it's the right look. john carpenter usually goes to a more natural look of colors. especially the skin tones in andrea's the thing look way to desaturated. which i think is a result of using a laserdisc color. we wont know for sure, unless mr. carpenter would watch that version and tells us if it's right or totally wrong.