Examine source code of Dark Negative

{
  "name": "Dark Negative",
  "manifest_version": 2,
  "version": "3.0",
  "theme": {
    "images": {
      "theme_frame": "Untitled-1-01.png"
    },
    "colors": {
      "toolbar": "rgba(41, 41, 41, 1)",
      "toolbar_field": "rgba(48, 48, 48, 1)",
      "toolbar_field_text": "rgba(255, 255, 255, 0.75)",
      "frame": "rgba(48, 48, 48, 1)",
      "tab_background_text": "rgba(255, 255, 255, 0.75)",
      "bookmark_text": "rgba(255, 255, 255, 0.75)"
    }
  }
}