Enhance "View>ShowOwners"

This is a useful feature that would be even better if it were more flexible.

For example, if you set land for sale, it still shows up as green like all your other land. It should be a different color: not green, not yellow, but something that says this is your land for sale.

Also, it would be useful if an officer could set a land color for the group. So that all of the land belonging to the group would show up as that color for people who are in the group.

Probably other enhancements would be useful too, but this would be a great and i hope fairly simple starting point.