Examine source code of SPACEPLAN

{
  "manifest_version": 2,
  "version": "2.0",
  "name": "SPACEPLAN",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.png"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right bottom"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(69, 72, 93, 0.66)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(21, 24, 51)",
      "tab_background_text": "rgb(69, 72, 93)",
      "toolbar_field": "rgb(22, 22, 22)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(6, 254, 195)",
      "popup": "rgb(21, 24, 51)",
      "popup_text": "rgb(255, 255, 255)",
      "ntp_background": "rgb(0, 0, 0)",
      "ntp_text": "rgb(255, 255, 255)",
      "tab_loading": "rgb(6, 254, 195)"
    }
  },
  "browser_specific_settings": {
    "geckium": {
      "backgroundImage": [
        "image1.png",
        "image2.png"
      ],
      "backgroundSize": "650px, cover",
      "backgroundPosition": "bottom left, center",
      "backgroundRepeat": "no-repeat",
      "attributionImage": "attribuition.png",
      "attributionWidth": "90px",
      "attributionHeight": "60px"
    },
    "gecko": {
      "id": "{ab4ac271-559a-4352-8980-8d33381e4c3e}"
    }
  }
}