Examine source code of Blue Titlebar Dark

{
  "manifest_version": 2,
  "version": "1.5.1",
  "name": "Blue Titlebar Dark",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-001-9c6d74e14860e77ee6f8f43e824bff25.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(51, 51, 51)",
      "toolbar_text": "rgb(232, 232, 232)",
      "frame": "rgb(0, 120, 215)",
      "tab_background_text": "rgb(234, 234, 234)",
      "toolbar_field": "rgb(44, 44, 44)",
      "toolbar_field_text": "rgb(234, 234, 234)",
      "tab_line": "rgba(97, 67, 125, 0)",
      "popup": "rgb(44, 44, 44)",
      "popup_text": "rgb(234, 234, 234)",
      "icons_attention": "rgb(49, 159, 245)",
      "popup_border": "rgb(38, 38, 38)",
      "popup_highlight_text": "rgb(234, 234, 234)",
      "popup_highlight": "rgb(0, 120, 215)",
      "sidebar_border": "rgb(38, 38, 38)",
      "sidebar_highlight_text": "rgb(234, 234, 234)",
      "sidebar_highlight": "rgb(0, 120, 215)",
      "sidebar_text": "rgb(234, 234, 234)",
      "sidebar": "rgb(44, 44, 44)",
      "toolbar_bottom_separator": "rgb(38, 38, 38)",
      "toolbar_field_border_focus": "rgb(0, 120, 215)",
      "toolbar_field_highlight_text": "rgba(234, 234, 234, 0.87)",
      "toolbar_field_highlight": "rgb(61, 117, 161)",
      "toolbar_top_separator": "rgb(0, 120, 215)",
      "tab_loading": "rgba(97, 67, 125, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{db7e2830-474e-4645-af37-1429acf1cf17}"
    }
  }
}