But there's just so much beautiful work that was done at a time when technology was so limited that it actually hurt the work!  The colorists themselves were severely limited in what the process allowed them to do. 

How far do we take the nostalgia side of the issue?  Isn't better paper changing the look?  Isn't crisper printing ruining that "nice muddy look" of old printing presses?

It's funny that people keep referring to the MARVEL MASTERWORKS as presenting the original work "warts and all" when it's their beautifully painted covers that inspired this thread!  I see those painted covers as one more stage in the process that wasn't available to Marvel in the 60's (due to time, money, or talent constraints).  Likewise with "recoloring"--if the new colorist considers the original colors as "flats" or just the first stage, is it really that bad to just add another stage to the process?  If Marvel had all its covers taken to the painted stage a week after Kirby drew them and somebody else inked them, is that any worse or better than Marvel having someone take it to the painted stage 50 years later?

But, yes, I would label it as "Recolored Edition" or similar.  And who knows?  Perhaps a little extra coloring effort could help open up the work of Ditko or other worthies to a whole new generation of fans.