Examine source code of Onion & Sienna

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Onion & Sienna",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-032-c7f80ac9e21af771c8d088973b1309ea.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(32, 41, 69)",
      "toolbar_text": "rgb(231, 125, 111)",
      "frame": "rgb(37, 37, 37)",
      "tab_background_text": "rgb(255, 250, 205)",
      "toolbar_field": "rgb(249, 248, 113)",
      "toolbar_field_text": "rgb(11, 8, 11)",
      "tab_line": "rgb(255, 255, 255)",
      "popup": "rgb(7, 50, 84)",
      "popup_text": "rgb(255, 255, 255)",
      "button_background_active": "rgb(184, 115, 255)",
      "button_background_hover": "rgb(255, 181, 98)",
      "icons": "rgb(255, 255, 255)",
      "ntp_background": "rgb(222, 86, 0)",
      "ntp_text": "rgb(255, 255, 255)",
      "popup_border": "rgb(255, 255, 255)",
      "popup_highlight_text": "rgb(255, 255, 255)",
      "popup_highlight": "rgba(231, 125, 111, 0.5)",
      "tab_loading": "rgb(255, 3, 3)",
      "tab_text": "rgb(231, 125, 111)",
      "toolbar_bottom_separator": "rgb(32, 41, 69)",
      "toolbar_field_focus": "rgb(37, 37, 37)",
      "toolbar_field_highlight_text": "rgb(255, 250, 205)",
      "toolbar_field_separator": "rgb(70, 79, 105)",
      "toolbar_field_text_focus": "rgb(255, 250, 205)",
      "toolbar_top_separator": "rgba(32, 41, 69, 0)",
      "toolbar_vertical_separator": "rgb(255, 20, 60)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{c7ee830d-814a-49d9-bcb2-f1133ff3108a}"
    }
  }
}