Bootstrap Variables

Is there a way for me to customize the bootstrap variables that are included in the theme? Variables such as $primary, etc? If not from the dashboard, any tips on doing it in the child theme?

The reason I ask is because it is nice to be able to add custom elements such as <a href="/" class="btn btn-primary">Button</a> and not be stuck with the default bootstrap variable styles.

I understand it would be possible to override the styles after the bootstrap files have been compiled, however it is not the same as changing the variables directly before compilation.