Examine source code of blue bubbles

{
  "theme": {
    "images": {
      "theme_frame": "themebub.jpg"
    },
    "colors": {
      "frame": "#707070",
      "tab_background_text": "#bfbfbf"
    }
  },
  "version": "2.0",
  "name": "blue bubbles",
  "manifest_version": 2,
  "description": "Blue Bubbles\n\n(My first theme hope it turns out good!)\n"
}