colorby unused?

[Kaixhin]

According to the docs, hiplot.Experiment has a colorby variable. It seems surprising that it can't be set in the init function though?

I searched the codebase and found it could just be set manually, so I tried this in my own code, but when I opened the plot (I'm using run_server), the colours seem to be based on a completely different column to the one I specified.