Examine source code of Octo's theme

{
  "name": "Octo's theme",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "image.psd.png"
    },
    "colors": {
      "frame": "rgba(36, 36, 36, 1)",
      "tab_background_text": "rgba(92, 92, 92, 1)",
      "toolbar": "rgba(56, 56, 56, 1)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(87, 87, 87, 1)",
      "toolbar_field_text": "rgba(113, 0, 248, 1)",
      "tab_line": "rgba(113, 0, 248, 1)"
    }
  }
}