Examine source code of Simple Color Picker

{
  "manifest_version": 2,
  "name": "Simple Color Picker",
  "version": "1.0",
  "description": "It is quite easy to develop such a client-side application. The primary colors as we know are Red(R), Green(G), Blue(B) and by mixing them we can form any color that we want. Extension, we will learn to get the RGB value from the user and use CSS to form the color using RGB(red, green, blue) property.",
  "permissions": [],
  "browser_action": {
    "default_popup": "game.html",
    "default_icon": {
      "128": "images/simple-logo.png"
    }
  },
  "icons": {
    "128": "images/simple-logo.png"
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{b88a9e6b-8c8b-414a-a9a9-d9540a9d3d4a}"
    }
  }
}