Examine source code of Gold & Dark Heightmap

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "CVI",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center center"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(25, 25, 25)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(41, 41, 41)",
      "tab_background_text": "rgb(187, 132, 72)",
      "toolbar_field": "rgb(41, 41, 41)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(187, 132, 72)",
      "popup": "rgb(25, 25, 25)",
      "popup_text": "rgb(255, 255, 255)",
      "icons": "rgb(187, 132, 72)",
      "tab_loading": "rgb(187, 132, 72)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{953f5450-b88e-4ba9-92b0-889c43475e88}"
    }
  }
}