Examine source code of Expresion_Musical.

{
  "theme": {
    "images": {
      "theme_frame": "ExpresinMsicalFirefox.jpg"
    },
    "colors": {
      "frame": "#f2f2f2",
      "tab_background_text": "#0a0909"
    }
  },
  "version": "2.0",
  "name": "Expresion_Musical.",
  "manifest_version": 2,
  "description": "¡Haciendo Arte con Propósito!"
}