Showing npm loading bar and colors on stdout

I'm using `shelljs` to run npm commands asynchronously like `npm install`. Can I display the `npm` loading bar and colors with `shelljs`? Currently only the raw text is output, so no color and no loading bar.

I'm using `exec` like this:

``` js
exec(`npm install "${name}@${version}"`, { async: true }, () => {
  …
})
```
