How to change button background color in v1.0.2?

[steven-twerdochlib]

This is about Bulma.

Overview of the problem

This is about the Bulma CSS framework

I'm using Bulma version [1.0.2]
My browser is: chrome

I am sure this issue is not a duplicate?

Description

Simple question that I can't figure out: How do I change the colour of a button background?
In 0.9.4 I simple did this: $button-background-color: transparent; before importing bulma but now $button-background-color: transparent; doesn't exist so what do I do instead?

Expected behavior

Button background colour to be transparent.

Actual behavior

Errors. error: [sass] This variable was not declared with !default in the @used module.

[PartishtaP]

Please assign me the issue.
I would like to contribute