How get :root scss variables from js in Ionic v4

Can someone help?

In variables.scss i have:
:root{
–ion-color-primary: #3880ff;
–ion-color-primary-rgb: 56, 128, ;255;
…e.g
}

How i can get them without overriding?

This not work:
const root = document.querySelector(’:root’);
const statusBarBackground = root.style.getPropertyValue(’–ion-color-primary’);