Examine source code of Gradation3

{
  "theme": {
    "images": {
      "theme_frame": "c.jpg"
    },
    "colors": {
      "frame": "#2fe00b",
      "tab_background_text": "#e68a09"
    }
  },
  "version": "2.0",
  "name": "Gradation3",
  "manifest_version": 2
}