Examine source code of Rainbow beat

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Rainbow beat",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center center"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(154, 132, 255)",
      "toolbar_text": "rgb(62, 62, 62)",
      "frame": "rgb(34, 46, 68)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgb(199, 255, 240)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(248, 0, 255)",
      "popup": "rgb(193, 193, 193)",
      "popup_text": "rgb(0, 6, 133)",
      "toolbar_field_border": "rgb(0, 255, 44)",
      "toolbar_field_focus": "rgb(255, 220, 199)",
      "toolbar_field_highlight_text": "rgb(227, 255, 0)",
      "toolbar_field_highlight": "rgb(28, 0, 255)",
      "tab_loading": "rgb(248, 0, 255)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{0840bb27-ca88-47f6-b54b-d32e4c30818d}"
    }
  }
}