Sample #4 of the new Vasari SDK samples is MassColorGrossFloorArea. The SDK sample contains code in both VB.NET and C#.
This is a rather interesting sample that implements IUpdater. This sample requires no command execution to update the materialism on a set of masses based on their relative closeness to a target Gross Floor Area (GFA). As the mass dimensions or applied mass floors are adjusting resulting in an updated GFA, the colors aromatically adjust to yellow if their GFA is under the allowable value for "Max Underage Gross Floor Area", red if over the "Max Overage Gross Floor Area", and green if within the allowable tolerance of the "Target Gross Floor Area" parameter. each of these parameters are type parameters within the mass family.
Here is a snapshot of the masses before they have been adjusted to be all within the GFA target.
Here is the masses all green after their dimensions have been adjusted to target their "Target Gross Floor Area" values.