Examine source code of Firefox Logo Orange Theme

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "rgba(229,230,232,1)",
      "tab_background_text": "#edeaea"
    }
  },
  "version": "2.0",
  "name": "Firefox Logo Orange Theme",
  "manifest_version": 2,
  "description": "---SIZE DOES ADJUST--- The photo appears to make the Firefox logo tiny but it adjusts once the theme is applied.  Simple Firefox logo theme."
}