That's widely reported, but not true. Maybe the first Hollywood movie to be released with full color correction.

The first movie that went thorough a complete digital processing step was the Swedish movie "Zingo" in the mid 90s. There is another one that got partially processed, but the name eludes me just now.

Anyway, Jason X was also color graded before O Brother Where Art Thou, but eventually did not get released for a couple of years.

It's probably correct that an obscure Swedish comedy didn't have any influence on modern editing techniques though, so I only consider those references valid for the question of who really did it first.