Vega-lite
Shapes and Colors
To use shapes and colors for data series, ensure that the data source is a STRING not NUMBER, then:
"mark": "point", // when using shape field in encoding "encoding": { "shape": {"field": "Name", "type": "nominal"}, "color": {"field": "Name", "type": "nominal"},
Size
You can use a hardcoded size for shapes and cirles:
"size": {"field": "Cylinders", "type": "quantitative"}
Or you can use a NUMBER as a quantitative type:
"size": {"value": 200}