Examine source code of Blue Base

{
  "name": "Blue Base",
  "manifest_version": 2,
  "version": "2.0",
  "theme": {
    "images": {
      "theme_frame": "transparent.png"
    },
    "colors": {
      "frame": "rgba(74, 105, 189, 1)",
      "tab_background_text": "rgba(255, 255, 255, 1)",
      "toolbar": "rgba(55, 60, 74, 1)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(55, 60, 74, 0)",
      "toolbar_field_text": "rgba(255, 255, 255, 1)",
      "tab_line": "rgba(30, 55, 153, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{ccdb198f-6cf5-4c1f-9955-ab7c78bf69cf}"
    }
  }
}