Examine source code of Valley theme

{
  "name": "Valley-theme",
  "manifest_version": 2,
  "version": "1.0",
  "theme": {
    "images": {
      "theme_frame": "Valley-theme.png"
    },
    "colors": {
      "frame": "rgba(229, 230, 232, 1)",
      "tab_background_text": "rgba(36, 212, 89, 1)",
      "toolbar": "rgba(230, 132, 129, 1)",
      "bookmark_text": "rgba(18, 230, 67, 1)",
      "toolbar_field": "rgba(166, 60, 48, 1)",
      "toolbar_field_text": "rgba(55, 199, 98, 1)"
    }
  },
  "browser_specific_settings": {
    "gecko": {
      "id": "{4b5ebbcb-b5d9-4d08-8808-64ae948ff8b1}"
    }
  }
}