$ npm install --global supports-color-cli

$ supports-color --help
  Usage
    $ supports-color
  Options
    --256  Check for 256 color support
    --16m  Check for 16 million color support
  Examples
    $ supports-color
    $ supports-color --256
    $ supports-color --16m
  Exits with code 0 if color is supported and 1 if not