Generated by SassMeister.com.

SassMeister-input.scss

// ----
// libsass (v3.1.0)
// ----

$config: (
  "color-red": red,
  "color-blue": blue,
  "color-black": black,
  "color-white": white,
  "font-body": 16px,
  "font-heading": 24px,
  "font-hero": 5rem,
);
@mixin properties-that-match($match, $map, $property) {
  @each $key, $value in $map {
    @if str-index($key, $match) {
      .#{$key} {
        #{$property}: $value;
      }
    }
  }
}

@include properties-that-match('color', $config, 'color');
@include properties-that-match('font', $config, 'font-size');

SassMeister-output.css

.color-red {
  color: red; }

.color-blue {
  color: blue; }

.color-black {
  color: black; }

.color-white {
  color: white; }

.font-body {
  font-size: 16px; }

.font-heading {
  font-size: 24px; }

.font-hero {
  font-size: 5rem; }