Examine source code of dark gray rising

{
  "theme": {
    "images": {
      "theme_frame": "dark_gray_rising_h.png"
    },
    "colors": {
      "frame": "#ff0000",
      "tab_background_text": "#ffffcc"
    }
  },
  "version": "2.0",
  "name": "dark gray rising",
  "manifest_version": 2,
  "description": "gradient rising from dark gray to white"
}