Global variables can be defined outside of an element in a :root pseudo-class:
:root {
--color-primary: #FFFFFF;
}
you can define a function like this:
@function color($color-name) {
@return var(--color-#{$color-name});
}
and call it into your sass:
body {
color: color(primary);
}
compiled sass code is:
body {
color: var(--color-primary);
}