Global css variables in Angular library project

I want to use global css vars in an Angular lib project like i do in normal projects:

Declare all variables in root scope in global.scss file

:root {
    --primary-color: #FF0000;
}

And then, in any component:

p {
    color: var(--primary-color);
}

global.scss is loaded in angular.json assets array but in library project this won't work. I've tried loading global.scss file from ng-package.json file in lib -> styleIncludePaths but it's not working at all (documentation).