Substring Status

{
  "$schema": "https://developer.microsoft.com/json-schemas/sp/v2/column-formatting.schema.json",
  "elmType": "div",
  "children": [
    {
      "elmType": "span",
      "attributes": {
        "iconName": "=if(indexOf(@currentField, 'Not Started') == 0, 'WarningSolid', if(indexOf(@currentField, 'In Progress') == 0, 'AirplaneSolid', 'CompletedSolid'))",
        "class": "='ms-fontColor-' + if(indexOf(@currentField, 'Not Started') == 0, 'redDark', if(indexOf(@currentField, 'In Progress') == 0, 'yellow', 'green'))",
        "title": "@currentField"
      },
      "style": {
        "font-size": "32px"
      }
    },
    {
      "elmType": "div",
      "style": {
        "padding-left": "4px"
      },
      "children": [
        {
          "elmType": "span",
          "txtContent": "=substring(@currentField, 0, indexOf(@currentField,':'))",
          "style": {
            "display": "inline-block",
            "width": "100%",
            "font-size": "10px",
            "line-height": "8px",
            "vertical-align": "text-top"
          }
        },
        {
          "elmType": "span",
          "txtContent": "=substring(@currentField, indexOf(@currentField,':') + 2, 100)",
          "style": {
            "display": "inline-block",
            "font-size": "14px",
            "font-weight": "bold",
            "vertical-align": "text-top",
            "line-height": "13px",
            "margin-top": "-4px"
          }
        }
      ]
    }
  ]
}