Examine source code of GlassMyFox

{
  "theme": {
    "images": {
      "theme_frame": "GlassMyFox_Header.png"
    },
    "colors": {
      "frame": "rgba(229,230,232,1)",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "GlassMyFox",
  "manifest_version": 2,
  "description": "Firefox Persona to go with the GlassMyFox add-on.\n\nTo make work the Accent color must be Transparent too. De-select \"Display Accent Color\" via the Personas Properties."
}