actually iam working on 3d based diagramms. For this i generated a point grid with different Z coords were i put Boxes on. Now i want to get different colors according to the z-coord. So low z-coord = white High z-coord = black everything between should be interpolated
use a Gradient object to define your colours, then evaluate the gradient at the different z-elevations. Use the resulting color as input for a Custom Preview component.
If you flatten the input G for the Preview Component you will see better results. However, I think your definition is not setup to distinguish between Z values but rather proximity to your influence points, so the colour gradient is white closer to the points black farther away. If I get a chance I'll have a better look at lunch time (3 hours away)
For future reference there is also a component that will determine the min and max bounds of a domain so you no longer have to use the list items. Scalar>Domain>Bounds, then use the domain components to access them individually.