Examine source code of Gromit Mug

{
  "name": "Gromit Mug",
  "manifest_version": 2,
  "version": "2.2.1",
  "theme": {
    "images": {
      "theme_frame": "GromitMugSmol.png"
    },
    "colors": {
      "frame": "rgba(210, 190, 155, 1)",
      "tab_background_text": "rgba(128, 107, 67, 1)",
      "toolbar_field_text": "rgba(51, 23, 12, 1)",
      "ntp_background": "rgb(235, 216, 192)"
    }
  }
}