{
  "$schema": "https://developer.microsoft.com/json-schemas/sp/v2/column-formatting.schema.json",
  "elmType": "div",
  "style": {
    "background-color": "=if(@currentField == '' , '' , if(@currentField < (((90) + (-30)) / 2) , 'rgba(' + if(@currentField < (-30) , 0 , (255 * (abs((@currentField) - (-30)) / (((90) - (-30)) / 2)))) + ',0 , 255 , 0.35)' , 'rgba(255,0,' + if(@currentField > (90) , 0 , (255 * (abs((90) - (@currentField)) / (((90) - (-30))/2)))) + ', 0.35)'))"
  },
  "children": [
    {
      "elmType": "div",
      "txtContent": "@currentField",
      "style": {
        "font-size": "20px",
        "font-weight": "bold",
        "margin-left": "10px"
      }
    }
  ]
}