Examine source code of Rainbow Integral

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "rainbowmath",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/0.jpg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "right center"
      ],
      "additional_backgrounds_tiling": [
        "no-repeat"
      ]
    },
    "colors": {
      "toolbar": "rgba(208, 89, 89, 0)",
      "toolbar_text": "rgb(18, 6, 69)",
      "frame": "rgb(0, 0, 0)",
      "tab_background_text": "rgb(18, 6, 69)",
      "toolbar_field": "rgb(248, 254, 252)",
      "toolbar_field_text": "rgb(18, 6, 69)",
      "tab_line": "rgb(255, 255, 255)",
      "popup": "rgb(248, 254, 252)",
      "popup_text": "rgb(18, 6, 69)",
      "tab_loading": "rgb(255, 255, 255)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{0fe929d7-9be7-4c55-b463-8590a53059d2}"
    }
  }
}