Examine source code of Looking Into Firefox

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#fcb55b",
      "tab_background_text": "#83fc19"
    }
  },
  "version": "2.0",
  "name": "Looking Into Firefox",
  "manifest_version": 2,
  "description": "\"With my big froggy eyes I have checked out many-a-browsers on my computer - Today I'm-a checking out Firefox!\""
}