Examine source code of Bluey Themey

{
  "manifest_version": 2,
  "version": "1.0",
  "name": "Bluey",
  "theme": {
    "images": {},
    "properties": {},
    "colors": {
      "toolbar": "rgb(76, 79, 89)",
      "toolbar_text": "rgb(255, 255, 255)",
      "frame": "rgb(47, 57, 127)",
      "tab_background_text": "rgb(215, 226, 239)",
      "toolbar_field": "rgb(54, 58, 89)",
      "toolbar_field_text": "rgb(255, 255, 255)",
      "tab_line": "rgb(205, 35, 185)",
      "popup": "rgb(24, 27, 43)",
      "popup_text": "rgb(215, 226, 239)",
      "tab_loading": "rgb(205, 35, 185)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{dcc1c2fe-9aff-4001-8f98-b9475c19e49b}"
    }
  }
}