I was approached twice with the question whether we offer colormaps/bars. In the overlay manager you can add/remove colorbars. However they are just dummy ones not connected to real nodes.

In my opinion the main questions/todos would be:

• Would it be of general interest to push the topic forward
• Are there some new insights / developements I am not aware of (@kalali mentioned the work of @jungsi)
• How to create a colorbar only for the topmost node
• How to handle interactions with other plugins
• Best loation for handling the respective code (since it involves interaction with VTK / vtkLookupTables etc)