Examine source code of Muji Overlay 01

{
  "name": "Muji Overlay 01",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "f-r2.png"
    },
    "colors": {
      "frame": "rgba(71, 88, 70, 1)",
      "tab_background_text": "rgba(215, 214, 195, 1)",
      "toolbar": "rgba(158, 158, 158, 0.3)",
      "toolbar_field": "rgba(34, 43, 52, 1)",
      "toolbar_field_text": "rgba(192, 191, 170, 1)",
      "tab_line": "rgba(71, 88, 70, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{f9879c74-0e47-45d4-a683-9e7c8798047d}"
    }
  }
}