[jwolfe]

Couldn't it be as simple as a list of (color, x, y, z) (base64 encoded) in the fragment? URL fragments can get really long.

Not sure what you'd need a look up key for.

[namdnay]

The lookup key would be if the backend stores all the generated towns, and you're just referencing them. But I think simple encoding as you say is more probable

[slingnow]

And how exactly would you represent these hypothetical stored towns?

Probably with a simple encoding.