Color Based Emojis

{
  "$schema": "https://developer.microsoft.com/json-schemas/sp/v2/column-formatting.schema.json",
  "elmType": "div",
  "style": {
    "background-color": "=if(@currentField == 'Green', '#2ECC71', if(@currentField == 'Yellow','#F1C40F', '#E74C3C'))",
    "color": "#fff",
    "white-space": "nowrap"
  },
  "children": [
    {
      "elmType": "span",
      "txtContent": "@currentField",
      "style": {
        "font-size": "2em",
        "display": "inline-block",
        "padding": "0 8px"
      },
      "attributes": {
        "iconName": "=if(@currentField == 'Green', 'Emoji2', if(@currentField == 'Yellow','EmojiNeutral', 'EmojiDisappointed'))"
      }
    }
  ]
}

{
  "$schema": "https://developer.microsoft.com/json-schemas/sp/column-formatting.schema.json",
  "elmType": "div",
  "style": {
    "background-color": {
      "operator": "?",
      "operands": [
        {
          "operator": "==",
          "operands": [
            "@currentField",
            "Green"
          ]
        },
        "#2ECC71",
        {
          "operator": "?",
          "operands": [
            {
              "operator": "==",
              "operands": [
                "@currentField",
                "Red"
              ]
            },
            "#E74C3C",
            {
              "operator": "?",
              "operands": [
                {
                  "operator": "==",
                  "operands": [
                    "@currentField",
                    "Yellow"
                  ]
                },
                "#F1C40F",
                {
                  "operator": "?",
                  "operands": [
                    {
                      "operator": "==",
                      "operands": [
                        "@currentField",
                        "Purple"
                      ]
                    },
                    "#76448A",
                    ""
                  ]
                }
              ]
            }
          ]
        }
      ]
    },
    "color": "#fff",
    "white-space": "nowrap"
  },
  "children": [
    {
      "elmType": "span",
      "txtContent": "@currentField",
      "style": {
        "font-size": "2em",
        "display": "inline-block",
        "padding": "0 8px"
      },
      "attributes": {
        "iconName": "=if(@currentField == 'Green', 'Emoji2', if(@currentField == 'Yellow','EmojiNeutral', 'EmojiDisappointed'))"
      }
    }
  ]
}