changing group color with if condition in json

I am a bit new to json and all. I wrote a program that can take in a txt file, read the header then rearrange the columns header,value into group that easier to look at.

I use javafx for GUI and json file to handle the grouping.

The program is working but i want to take it one step further. I want the color of that group change from , for example, black to red whenever the value exceed a certain threshold.

So how would i do that in json file? what is the syntax of if else ? Can you give me an example base on the snippet of the code ? Thanks

json file:

[
  {
    "id": 1,
    "name": "Magtitue",
    "columnNames": [
      "magx",
      "right mag",
      "magy",
      "forward mag",
      "magz",
      "down mag"
    ],
    "color": "red"
  },
  {
    "id": 2,
    "name": "Flight Time",
    "columnNames": [
      "flighttime",
      "flight time"
    ],
    "color": "green"
  },
  {
    "id": 3,
    "name": "Temperature",
    "columnNames": [
      "temperature"
    ],
    "color": "blue"
  }
]

java handler that use json file:

@ToString
@Data
public class ColumnGroupInfo implements Comparable {

    private static final Gson GSON = new Gson();
    private int id;
    private String name;
    private String color;
    private List<String> columnNames = new LinkedList<>();

    public ColumnGroupInfo(int id, String name, String color) {
        super();
        this.id = id;
        this.name = name;
        this.color = color;
    }

    public static ColumnGroupInfo newInstance(JSONObject json) {
        ColumnGroupInfo ent = GSON.fromJson(json.toString(), ColumnGroupInfo.class);
        return ent;
    }

    public int getId() {
        return id;
    }


    public void setId(int id) {
        this.id = id;
    }


    public String getName() {
        return name;
    }


    public void setName(String name) {
        this.name = name;
    }


    public String getColor() {
        return color;
    }


    public void setColor(String color) {
        this.color = color;
    }


    public List<String> getColumnNames() {
        return columnNames;
    }


    public void setColumnNames(List<String> columnNames) {
        this.columnNames = columnNames;
    }

    @Override
    public boolean equals(Object obj) {

        if (!(obj instanceof ColumnGroupInfo)) {
            return false;
        }
        ColumnGroupInfo columnGroupInfo = (ColumnGroupInfo) obj;
        return columnGroupInfo.id == this.id &&
                columnGroupInfo.name.equals(this.name) &&
                columnGroupInfo.columnNames.equals(this.columnNames);

    }

    @Override
    public String toString() {
        return String.format("id:%s,name:%s,color:%s", id, name, color);
    }


    @Override
    public int compareTo(Object o) {
        if (o instanceof ColumnGroupInfo) {
            ColumnGroupInfo compare = (ColumnGroupInfo) o;
            return Integer.compare(getId(), compare.getId());
        }
        return 0;
    }
}