Examine source code of Blue grey-ish

{
  "name": "Blue grey-ish",
  "manifest_version": 2,
  "version": "8.0",
  "theme": {
    "images": {
      "theme_frame": "newcanvas_1553108912367.png"
    },
    "colors": {
      "toolbar": "rgba(204, 208, 224, 1)",
      "toolbar_field": "rgba(240, 240, 255, 1)",
      "toolbar_field_text": "rgba(163, 163, 163, 1)",
      "frame": "rgba(0, 0, 0, 1)",
      "tab_background_text": "rgba(115, 114, 114, 1)",
      "bookmark_text": "rgba(77, 75, 94, 1)"
    }
  }
}