Examine source code of Dolphin by balfin

{
  "theme": {
    "images": {
      "theme_frame": "persona_balfin.jpg"
    },
    "colors": {
      "frame": "#1e7bf5",
      "tab_background_text": "#f7f4f4"
    }
  },
  "version": "2.0",
  "name": "Dolphin by balfin",
  "manifest_version": 2,
  "description": "Delfines mulares"
}