Wells properties should be optional

The MD, name and color properties on wells should be optional.

- [ ] default color should be used if not specified, suggested is solid black
- [ ] readout and hover should show sensible information if name or MD is missing

Locate the wells property definitions and the code that renders readouts and hover content; the issue does not name specific files or tests. Verify that missing MD, name, and color values render sensible information and that unspecified color uses solid black.

Written by the indexing model from the issue text.