What are themes?

A theme is a special kind of extension that changes the way the browser looks. Themes are packaged like regular extensions, but they don't contain JavaScript or HTML code.

Themes are uploaded to the Chrome Web Store using the same procedure as an extension. During upload, you'll be asked to select a category. You'll find a list of theme categories in Chrome Web Store documentation under Best practices.

You can find and try a bunch of themes at the Chrome Web Store.

green plants theme

love smoke theme

jus d'orange theme

Manifest

Here is an example manifest.json file for a theme:

{
  "manifest_version": 3,
  "version": "2.6",
  "name": "camo theme",
  "theme": {
    "images" : {
      "theme_frame" : "images/theme_frame_camo.png",
      "theme_frame_overlay" : "images/theme_frame_stripe.png",
      "theme_toolbar" : "images/theme_toolbar_camo.png",
      "theme_ntp_background" : "images/theme_ntp_background_norepeat.png",
      "theme_ntp_attribution" : "images/attribution.png"
    },
    "colors" : {
      "frame" : [71, 105, 91],
      "toolbar" : [207, 221, 192],
      "ntp_text" : [20, 40, 0],
      "ntp_link" : [36, 70, 0],
      "ntp_section" : [207, 221, 192],
      "button_background" : [255, 255, 255]
    },
    "tints" : {
      "buttons" : [0.33, 0.5, 0.47]
    },
    "properties" : {
      "ntp_background_alignment" : "bottom"
    }
  }
}

colors

Colors are in RGB format. To find the strings you can use within the "colors" field, see kOverwritableColorTable.