Examine source code of FireTheme Ultimate

{
  "name": "FireTheme Ultimate",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "firefox.png"
    },
    "colors": {
      "frame": "rgba(255, 255, 255, 1)",
      "tab_background_text": "rgba(233, 247, 140, 1)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(88, 57, 105, 0.43)",
      "toolbar_field_text": "rgba(191, 140, 219, 1)"
    }
  }
}