Ohh, it said it was updated 23 days ago in the details. The only thing I've found when using it is that the suggestions can be hit or miss. For example, if I have a dark green and I use the tool, it shows a much lighter super saturated green (like neon). I've programmed in LUA, not sure how you'd even account for that though. Some colors just need to have sat adjusted or they become muted, or overpowered. It works great 80% of the time though!
Ah! I think I changed something in the description on ith.io, but I didn't touch the code. As for obtaining colors, it follows a fixed formula (it's a pretty small and simple script). ColorCalc follows a reference formula (which makes it more open, but less “practical” precisely because it needs that reference). As you can see, I've tried to address the issue of color in some scripts, but the good thing (and what makes it very difficult) is that there are no correct colors, only personal tastes.