Examine source code of James White v2

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "rgba(229,230,232,1)",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "James White v2",
  "manifest_version": 2,
  "description": "Trying to fit the old \"James White\" theme from Chrome into the right proportions for the new versions of Firefox. All credits to him and the creator of the original theme, of course."
}