Examine source code of Dark Day pain

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#1b34b3",
      "tab_background_text": "#0ca691"
    }
  },
  "version": "2.0",
  "name": "Dark Day pain",
  "manifest_version": 2,
  "description": "simple,dark,metalic"
}