vega 2

{
  "$schema": "https://vega.github.io/schema/vega-lite/v3.json",
  "data": {
    "values" : [
    {"xOffset" : -6, "yOffset" : -10, "loss" : 24.922490927655154},
    {"xOffset" : 1, "yOffset" : -10, "loss" : 0.060472122313392},
    {"xOffset" : 6, "yOffset" : -10, "loss" : 25.535235442853004},

    {"xOffset" : -6, "yOffset" : 1, "loss" : 20},
    {"xOffset" : 1, "yOffset" : 1, "loss" : 7},
    {"xOffset" : 6, "yOffset" : 1, "loss" : 9},

    {"xOffset" : -6, "yOffset" : 10, "loss" : 21},
    {"xOffset" : 1, "yOffset" : 10, "loss" : 9},
    {"xOffset" : 6, "yOffset" : 10, "loss" : 8} 
    ]},
  "mark": "bar",
  "selection": {
    "highlight": {"type": "single"}
  },
  "config": {
    "scale": {
      "bandPaddingInner": 0,
      "bandPaddingOuter": 0,
      "rangeStep": 40
  },
  "range": {
      "ramp": {
        "scheme": "yellowgreenblue"
      }
    }
  },
  "encoding" : {
    "x" : {
      "field": "xOffset",
      "type" : "nominal"
    },
    "y" : {
      "field" : "yOffset",
      "type" : "nominal"
    },
    "color" : {
      "field" : "loss",
      "type" : "quantitative"
    }
  }
}