Yeah, I know where you can buy it online, but I've only ever found it once in a store, and it was $300+. Thats ridiculous for what I'd use it for! And I don't have that store near me either, ah well.
I have Paintshop Pro 7 myself, but I don't ever use it. I should probably learn how to use the more advanced options. I could probably achieve the same results with some tinkering.
As far as how Okari does it, I don't know. Its probably a filter. Alot of the work is done for you by the computer. One of the reasons I prefer regular coloring over having it done through a computer.