At the moment its only a stripped down Bulma with some slight modification but planning to developed it further as a personal css framework with automated tests and maybe a gui build system to set some default variables..
Check src/scss/vars/variables.scss and src/scss/vars/colors.scss and add those to your variables (remove the !default statement and import them first):
@import 'my-vars';
@import '../bower_components/flexomatic/src/scss/flexomatic';
@import 'layout';
...