{
  "description": "A bubbleplot showing horsepower on x, miles per gallons on y, and weight with a diverging color scale.",
  "data": {"url": "data/cars.json"},
  "mark": "point",
  "encoding": {
    "x": {"field": "Horsepower","type": "quantitative"},
    "y": {"field": "Miles_per_Gallon","type": "quantitative"},
    "color": {
      "field": "Weight_in_lbs",
      "type": "linear",
      "scale": {
        "domain": [1000,2750,4500],
        "range": ["#ff7f0e","#e7ba52","#17becf"]
      }
    }
  }
}

{
  "description": "A bubbleplot showing horsepower on x, miles per gallons on y, and weight with a diverging color scale.",
  "data": {"url": "data/cars.json"},
  "mark": "point",
  "encoding": {
    "x": {"field": "Horsepower","type": "quantitative"},
    "y": {"field": "Miles_per_Gallon","type": "quantitative"},
    "color": {
      "field": "Weight_in_lbs",
      "type": "quantitative",
      "scale": {
        "domain": [1000,2750,4500],
        "range": ["#ff7f0e","#e7ba52","#17becf"]
      }
    }
  }
}

Fix example spec for @zoe
Fix example spec for @zoe
