Examine source code of Colour mosaic

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Colour mosaic",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center center"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(241, 241, 241, 0.5)",
      "toolbar_text": "rgb(49, 49, 49)",
      "frame": "rgb(192, 192, 192)",
      "tab_background_text": "rgb(0, 0, 0)",
      "toolbar_field": "rgb(255, 255, 255)",
      "toolbar_field_text": "rgb(73, 121, 255)",
      "tab_line": "rgb(255, 205, 138)",
      "popup": "rgb(245, 255, 233)",
      "popup_text": "rgb(170, 25, 255)",
      "ntp_background": "rgb(255, 226, 235)",
      "ntp_text": "rgb(212, 88, 0)",
      "tab_loading": "rgb(255, 205, 138)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{142ae6f7-a992-4841-a215-56ad1cf3b36b}"
    }
  }
}