Examine source code of Impromptus

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "2612-1",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(85, 85, 85, 0.83)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(89, 89, 89)",
      "tab_background_text": "rgb(255, 255, 255)",
      "toolbar_field": "rgba(0, 0, 0, 0.61)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgba(255, 255, 255, 0.6)",
      "popup": "rgb(85, 85, 85)",
      "popup_text": "rgb(255, 255, 255)",
      "button_background_active": "rgb(112, 112, 112)",
      "button_background_hover": "rgba(0, 0, 0, 0.59)",
      "icons_attention": "rgb(255, 90, 0)",
      "icons": "rgb(255, 255, 255)",
      "ntp_background": "rgba(115, 115, 115, 0.66)",
      "ntp_text": "rgb(255, 255, 255)",
      "popup_border": "rgba(121, 121, 121, 0.66)",
      "popup_highlight_text": "rgb(255, 255, 255)",
      "sidebar_border": "rgba(121, 121, 121, 0.66)",
      "sidebar_highlight_text": "rgb(255, 255, 255)",
      "sidebar_highlight": "rgba(0, 0, 0, 0.66)",
      "sidebar_text": "rgb(255, 255, 255)",
      "sidebar": "rgb(85, 85, 85)",
      "tab_loading": "rgb(146, 146, 146)",
      "tab_selected": "rgba(48, 48, 48, 0.82)",
      "tab_text": "rgb(255, 255, 255)",
      "toolbar_bottom_separator": "rgba(77, 77, 77, 0.82)",
      "toolbar_field_border_focus": "rgba(0, 0, 0, 0.7)",
      "toolbar_field_border": "rgba(125, 125, 125, 0.84)",
      "toolbar_field_focus": "rgba(180, 180, 180, 0.66)",
      "toolbar_field_highlight_text": "rgb(255, 255, 255)",
      "toolbar_field_highlight": "rgb(82, 82, 82)",
      "toolbar_field_separator": "rgb(255, 255, 255)",
      "toolbar_field_text_focus": "rgb(0, 0, 0)",
      "toolbar_top_separator": "rgba(191, 191, 191, 0.57)",
      "toolbar_vertical_separator": "rgb(255, 255, 255)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{76abe917-020e-414d-92e5-987e2720c390}"
    }
  }
}