Generated by SassMeister.com.

input.scss

$color: #ffc107;

@debug lightness($color);
html {
    background: lighten($color, 39.2%);
}

output.css

html {
  background: #fff3cf;
}

settings.json

{
  "sass": {
    "compiler": "dart-sass/1.26.11",
    "extensions": {},
    "syntax": "SCSS",
    "outputStyle": "expanded"
  },
  "autoprefixer": false
}