Examine source code of monochrome

{
  "name": "monochrome",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "tropical-green-leaves-background.jpg"
    },
    "colors": {
      "frame": "rgba(59, 64, 74, 1)",
      "tab_background_text": "rgba(0, 0, 0, 1)",
      "toolbar": "rgba(189, 189, 189, 1)",
      "bookmark_text": "rgba(77, 77, 77, 1)",
      "toolbar_field": "rgba(173, 173, 173, 1)",
      "toolbar_field_text": "rgba(125, 125, 125, 1)",
      "tab_line": "rgba(255, 255, 255, 0)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{3293da7a-a08e-4b84-8755-5d4728f70c9b}"
    }
  }
}