Examine source code of A nice one

{
  "name": "A nice one",
  "version": "1.0",
  "description": "",
  "manifest_version": 2,
  "theme": {
    "images": {
      "theme_frame": "images/theme_frame.png",
      "theme_toolbar": "images/theme_toolbar.png",
      "theme_tab_background": "images/theme_tab_background.png",
      "theme_ntp_background": "images/theme_ntp_background.png"
    },
    "colors": {
      "frame": [
        28,
        28,
        28
      ],
      "toolbar": [
        20,
        20,
        20
      ],
      "tab_text": [
        151,
        147,
        147
      ],
      "tab_background_text": [
        133,
        130,
        130
      ],
      "bookmark_text": [
        147,
        238,
        27
      ],
      "ntp_background": [
        255,
        255,
        255
      ],
      "ntp_text": [
        50,
        50,
        50
      ],
      "ntp_link": [
        6,
        55,
        116
      ],
      "button_background": [
        0,
        0,
        0,
        0
      ]
    },
    "tints": {
      "buttons": [
        0,
        0,
        0.69
      ]
    },
    "properties": {
      "ntp_background_alignment": "bottom",
      "ntp_background_repeat": "no-repeat"
    }
  }
}