We will set you up with some defaults, like red=cut and grey = engrave 50%, that will automatically import correctly. You can then override those, or use nonstandard colors and assign them. We’re still figuring out what the right design language is for this. I’m copying my cofounder @Tony on this, who’s the person working on it. Maybe he can float some of our design proposals here for feedback when they’re ready.
As far as Glowforge designs - Settlers was a one-off because of some crazy circumstances surrounding it (front page of reddit, deal with Mayfair games). We’re not planning on releasing more free patterns right now. Tell me if you think that’s wrong, though, we’re always open to listening.