Examine source code of Daves Here

{
  "theme": {
    "images": {
      "theme_frame": "DavesFirefoxHeader.jpg"
    },
    "colors": {
      "frame": "#20cad6",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Daves Here",
  "manifest_version": 2,
  "description": "Dave's Here! text in white with a slight gradient in aquamarine."
}