Examine source code of grn

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "grn",
  "theme": {
    "images": {
      "additional_backgrounds": [
        "images/bg-010-e9f94a3e61666a4c7677eb9cce17d854.svg"
      ]
    },
    "properties": {
      "additional_backgrounds_alignment": [
        "top"
      ],
      "additional_backgrounds_tiling": [
        "repeat"
      ]
    },
    "colors": {
      "toolbar": "rgb(255, 255, 255)",
      "toolbar_text": "rgb(21, 94, 3)",
      "frame": "rgb(132, 195, 145)",
      "tab_background_text": "rgb(0, 0, 0)",
      "toolbar_field": "rgb(255, 255, 255)",
      "toolbar_field_text": "rgb(0, 0, 0)",
      "tab_line": "rgb(4, 93, 21)",
      "popup": "rgb(255, 255, 255)",
      "popup_text": "rgb(0, 0, 0)",
      "tab_loading": "rgb(4, 93, 21)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{9812408a-5d96-4473-9bd5-9df23205e127}"
    }
  }
}