Examine source code of Electric Dark Blue

{
  "name": "Electric Dark Blue",
  "manifest_version": 2,
  "version": "1.7",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "firefox-back.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "frame": "rgba(35, 35, 35, 1)",
      "tab_background_text": "rgba(130, 130, 130, 1)",
      "bookmark_text": "rgba(106, 165, 255, 1)",
      "toolbar": "rgba(71, 71, 71, 1)",
      "toolbar_field": "rgba(35, 35, 35, 1)",
      "toolbar_field_text": "rgba(106, 165, 255, 1)",
      "toolbar_field_border_focus": "rgba(106, 165, 255, 1)",
      "toolbar_highlight": "rgba(106, 165, 255, 1)",
      "toolbar_highlight_text": "#fff",
      "tab_line": "rgba(106, 165, 255, 1)",
      "ntp_background": "rgba(52, 52, 52, 1)",
      "ntp_text": "rgba(230, 230, 230, 1)",
      "popup": "rgba(52, 52, 52, 1)",
      "popup_text": "rgba(230, 230, 230, 1)",
      "popup_border": "rgba(62, 62, 62, 1)",
      "popup_highlight": "rgba(106, 165, 255, 1)",
      "popup_highlight_text": "#fff",
      "sidebar": "rgba(71, 71, 71, 1)",
      "sidebar_text": "rgba(230, 230, 230, 1)",
      "sidebar_highlight": "rgba(106, 165, 255, 1)",
      "sidebar_highlight_text": "#fff"
    }
  }
}