bootstrap btn style css code example

Example 1: bootstarp btn colors

<button type="button" class="btn btn-primary">Blue</button>
<button type="button" class="btn btn-secondary">Grey</button>
<button type="button" class="btn btn-success">Green</button>
<button type="button" class="btn btn-danger">Red</button>
<button type="button" class="btn btn-warning">Yellow</button>
<button type="button" class="btn btn-info">Ligth blue</button>
<button type="button" class="btn btn-light">White</button>
<button type="button" class="btn btn-dark">Black</button>

<button type="button" class="btn btn-link">White with blue text</button>

Example 2: btn-default class in bootstrap 4

<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css" integrity="sha384-Gn5384xqQ1aoWXA+058RXPxPg6fy4IWvTNh0E263XmFcJlSAwiGgFAW/dAiS6JXm" crossorigin="anonymous">

<div class="container m-3">
    <a class="btn btn-outline-secondary">outline-secondary link</a>
    <button type="button" class="btn btn-outline-secondary">outline-secondary 'button'</button>
    <br><br>
    <a class="btn btn-outline-light">outline-light link</a>
    <button type="button" class="btn btn-outline-light">outline-light 'button'</button>
</div>