Examine source code of Become brighter. .

{
  "theme": {
    "images": {
      "theme_frame": "0527-akarukunatteiku-syx.jpg"
    },
    "colors": {
      "frame": "#daf3f5",
      "tab_background_text": "#fcf7f7"
    }
  },
  "version": "2.0",
  "name": "Become brighter. .",
  "manifest_version": 2,
  "description": "明るくなっていく。。\n\n\n\n0527-akarukunatteiku-syx"
}