Examine source code of Vivid Pixels

{
  "theme": {
    "images": {
      "theme_frame": "header.png"
    },
    "colors": {
      "frame": "#000000",
      "tab_background_text": "#ffffff"
    }
  },
  "version": "2.0",
  "name": "Vivid Pixels",
  "manifest_version": 2,
  "description": "(You need to preview to see the pixel design) This subtle theme combines a calm blurry colourful gradient with the addition with a harsh pixel design on top to produce an unusual contrast between the blurry colours and the black pixel design."
}