Examine source code of Mixed Plum Colours

{
  "name": "Mixed Plum Colours",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "firefox.bkg.template.png"
    },
    "colors": {
      "frame": "rgba(138, 5, 54, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(74, 6, 64, 1)",
      "bookmark_text": "rgba(255, 194, 10, 1)",
      "toolbar_field_text": "rgba(138, 5, 54, 1)",
      "tab_line": "rgba(0, 0, 0, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{93629fb4-893f-4f8a-a10f-a21a288be90e}"
    }
  }
}