interactive_paintbrush_color.vl.json

{
  "$schema": "https://vega.github.io/schema/vega-lite/v4.json",
  "description": "Select multiple points with the shift key.",
  "data": {"url": "data/cars.json"},
  "params": [{
    "name": "paintbrush",
    "select": {
      "type": "multi",
      "on": "mouseover"
    }
  }],
  "mark": "circle",
  "encoding": {
    "x": {"field": "Horsepower", "type": "quantitative"},
    "y": {"field": "Miles_per_Gallon", "type": "quantitative"},
    "color": {
      "condition": {
        "selection": "paintbrush",
        "field": "Cylinders", "type": "ordinal"
      },
      "value": "grey"
    },
    "size": {"value": 75}
  }
}