Examine source code of Night Swim (Animated)

{
  "manifest_version": 2,
  "version": "1.3",
  "name": "Night Swim (Animated)",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png",
        "images/1.png",
        "images/2.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "center top",
        "center top",
        "center top"
      ],
      "additional_backgrounds_tiling": [
        "repeat-x",
        "repeat-y",
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(9, 36, 70, 0.8)",
      "toolbar_text": "rgba(196, 221, 255, 0.9)",
      "frame": "rgb(0, 0, 0)",
      "tab_background_text": "rgb(155, 196, 255)",
      "toolbar_field": "rgba(0, 0, 0, 0.75)",
      "toolbar_field_text": "rgba(196, 221, 255, 0.9)",
      "tab_line": "rgb(125, 183, 255)",
      "popup": "rgba(9, 36, 70, 0.9)",
      "popup_text": "rgba(196, 221, 255, 0.9)",
      "tab_loading": "rgb(125, 183, 255)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{049454fb-25cf-4778-8182-de970aef7f0c}"
    }
  }
}