Examine source code of slate-theme-ffox

{
  "name": "slate",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "000.png"
    },
    "colors": {
      "frame": "rgba(0, 0, 0, 1)",
      "tab_background_text": "rgba(235, 235, 235, 1)",
      "toolbar": "rgba(23, 23, 23, 1)",
      "bookmark_text": "rgba(255, 255, 255, 1)",
      "toolbar_field": "rgba(74, 74, 74, 1)",
      "toolbar_field_text": "rgba(232, 232, 232, 1)"
    }
  }
}