FixIt/assets/css/_core/_root.scss

:root {
  // Note: Custom variable values only support SassScript inside `#{}`.

  // Theme colors varibles
  @each $color, $value in $theme-colors {
    --#{$prefix}#{$color}: #{$value};
  }
  @each $color, $value in $theme-colors {
    --#{$prefix}#{$color}-dark: #{darken($value, 5%)};
  }
}