Just tried the scripts and they work only on a library of function that is outdated and no longer available anyway planned for max 4 ... so is there another way atm ?
This might help. I've never tried it myself, but I've seen it around. http://www.scriptspot.com/3ds-max/scripts/vertex-color-tools-0 reads: "Adjust R -G -B -H -S -V -Contrast"
I think that script is now part of max or am I wrong? It should be doable what you want to do with standard tools. Just go trough them. Opening Help reveals also a lot about not that much used features.. ;)