There are button styles for various colours, as well as block and inline. A small inline button has reduced horizontal padding.
By default, buttons are uppercase. You can change the case by the addition of lowercase or normal-case classes.
<button class="button button--red--dark ">
<span>Dark Red Button</span>
</button>
{{#if button.link}}
<a href="{{ button.link }}" class="{{modifier _self.baseHandle button.modifiers}} {{ button.classes }}">
<span>{{ button.text }}</span>
</a>
{{else}}
<button class="{{modifier _self.baseHandle button.modifiers}} {{ button.classes }}">
<span>{{ button.text }}</span>
</button>
{{/if}}