Colors

A button can have different colors

<button class="wojo button">
  default
</button>
<button class="wojo basic button">
  basic
</button>
<button class="wojo primary button">
  primary
</button>
<button class="wojo secondary button">
  secondary
</button>
<button class="wojo positive button">
  positive
</button>
<button class="wojo negative button">
  negative
</button>
<button class="wojo black button">
  black
</button>