Examine source code of Animated: Tokyo Dark

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Tokyo Dark",
  "description": "Tokyo Night inspired dark theme with animated rain header",
  "icons": {
    "128": "images/icon.png"
  },
  "theme": {
    "colors": {
      "toolbar": "#1a1b26",
      "frame": "#1a1b26",
      "tab_background_text": "#a9b1d6",
      "toolbar_field": "#292e42",
      "toolbar_field_text": "#c0caf5",
      "tab_line": "transparent",
      "popup": "#24283b",
      "popup_text": "#c0caf5",
      "popup_border": "#414868",
      "popup_highlight": "#3d59a1",
      "popup_highlight_text": "#c0caf5",
      "sidebar_border": "#414868",
      "sidebar_highlight": "#3d59a1",
      "sidebar_highlight_text": "#c0caf5",
      "sidebar_text": "#c0caf5",
      "sidebar": "#292e42",
      "tab_loading": "#7aa2f7",
      "tab_selected": "#3d59a1",
      "tab_text": "#c0caf5",
      "toolbar_field_border_focus": "#7aa2f7",
      "toolbar_field_highlight": "#3d59a1",
      "toolbar_field_highlight_text": "#c0caf5",
      "button_background_hover": "#3d59a1",
      "button_background_active": "#3d59a1",
      "icons": "#c0caf5",
      "icons_attention": "#7aa2f7",
      "toolbar_top_separator": "#1a1b26",
      "ntp_background": "#1a1b26",
      "ntp_text": "#c0caf5",
      "bookmark_text": "#c0caf5",
      "toolbar_button_icon": "#a9b1d6",
      "identity_block": "#24283b"
    },
    "images": {
      "additional_backgrounds": [
        "images/header.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{ff2dbbf1-364a-43ae-9678-8c26e15c29af}"
    }
  }
}