Hey using Umbraco 13, does anyone know how to limit colours available from the colour picker in the rich text editor?

I have managed to get a colour picker by using the following in my appsettings

   "RichTextEditor": {
      "Commands": [
        {
          "Alias": "forecolor",
          "Name": "Color Picker",
          "mode": "Selection"
        }
      ],
      "Plugins": [],
      "CustomConfig": {
        "color_map": [
          "000000",
          "Black",
          "a4b69c",
          "Green"
        ]

    }
    }

Which enables me to select the colour picker on the property editor:

Then it displays a colour picker on the editor. However, the colours are not limited

I have tried using textcolor_map

"CustomConfig": {
  "textcolor_map": [
    "000000", "Black",
    "a4b69c",  "Green"
  ],

and also using

 "color_picker": false

But nothing seems to work. Any suggestions, I can try?