Examine source code of gradient biohazard

{
  "theme": {
    "images": {
      "theme_frame": "firefox-header.jpg"
    },
    "colors": {
      "frame": "#0d0d0d",
      "tab_background_text": "#a80000"
    }
  },
  "version": "2.0",
  "name": "gradient biohazard",
  "manifest_version": 2,
  "description": "mehh, first design, went bad. might fix it later."
}