when I create subclasses of PortObject and PortObjectSpec, the ports on the nodes are always shown as grey squares. However, the PMML output port of e.g. the Naive Bayes Learner has blue squares. Is there a way to customize my own port types' look?
I will answer this myself: (at least with KNIME 2.11) it does not seem to be possible. The colors are defined in:
However, I would really love to see a customizability here, as it would ease working with nodes with different custom types.