Button custom outline colors

Modern outline buttons implementation with more range of colors.

Example

<!-- Source -->
<button class="btn btn-outline-link" type="button">Link</button>
<button class="btn btn-outline-black" type="button">Black</button>
<button class="btn btn-outline-indigo" type="button">Indigo</button>
<button class="btn btn-outline-orange" type="button">Orange</button>
<button class="btn btn-outline-pink" type="button">Pink</button>
<button class="btn btn-outline-purple" type="button">Purple</button>
<button class="btn btn-outline-teal" type="button">Teal</button>
<button class="btn btn-outline-white" type="button">White</button>