Examine source code of Dark Gray for Base

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#540f0f",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Dark Gray for Base",
  "manifest_version": 2,
  "description": "This is a dark grey solid theme to match the gray from a windows 8.1 theme called \"base for windows 8.1\""
}