Special properties derived from analysis of layout.objectDescriptor metadata (e.g. a user object and now an "array of classification "structure") are marked in the background color of the navigator's treeview viewmodel using lighten/darken rations and hue shift parameters. This is ultimately more flexible than fixed values and allows for potentially more dimensions to be encoded using various color transformations.? For now it's probably as rich as necessary (if not a little too rich given the newness of the metaphor I seek to convey with seemingly simply tree structures).