Examine source code of Echo

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Echo",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-000-5672c42860d5b06e1058dc477397f3ef.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(36, 54, 70)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(22, 36, 50)",
      "tab_background_text": "rgb(100, 156, 189)",
      "toolbar_field": "rgb(36, 50, 61)",
      "toolbar_field_text": "rgb(118, 180, 216)",
      "tab_line": "rgb(118, 180, 216)",
      "popup": "rgb(36, 53, 61)",
      "popup_text": "rgb(118, 180, 216)",
      "button_background_active": "rgb(118, 180, 216)",
      "frame_inactive": "rgb(20, 30, 39)",
      "ntp_background": "rgb(22, 36, 50)",
      "sidebar_border": "rgb(100, 156, 189)",
      "sidebar_highlight": "rgb(118, 180, 216)",
      "tab_loading": "rgb(118, 180, 216)"
    }
  }
}