Here's a few tests I did. Some tips below on improving your results.
1. For some reason, this plugin works best if you put it BEFORE the pan/crop in the plugin chain.
2. From there, color grade to correct any imperfections as much as you can.
3. While I didn't do it here, rotoscope/mask objects out so you can isolate them, then run the colorize effect on just those objects/people, would likely produce the best results.
4. AI won't guess the right or most desirable color every time, so use hue shift to change them to your liking.
Reefer Madness:
Wizard of Oz (note, this last one was done on an earlier version of the plugin, results have improved since):
The tech behind this, since it is identifying objects in the scene and then guessing what those objects should be colored based on what it thinks they are, can also be expanded upon in the future to enable the automatic generation of masks, even moving masks! The AI already identifies "this is a person", "this is a tree", etc... so it just needs to mask around those objects afterwards to work (I'm sure that's WAY oversimplifying it, but the basic concept is there). So, I wouldn't be surprised at all if an auto-rotoscoping feature ends up coming to VEGAS in the near future.
Post your results and techniques here!