chrome/test/data/extensions/manifest_tests/theme_color.json

{
  "name": "Theme Color",
  "manifest_version": 2,
  "version": "1",
  "app": {
    "launch": {
      "web_url": "http://www.google.com/launch.html"
    },
    "theme_color": "rgba(255, 0, 0, 0.5)"
  }
}