Generated by SassMeister.com.

SassMeister-input.scss

// ----
// libsass (v0.8.6)
// ----

$transp: rgba(255,255,255,0);

$colors-warm:  violet, teal, steelblue, skyblue, yellowgreen, yellow, gold, orange, crimson, purple;

$warm: (
  colors: $colors-warm,
  bg-color: orangered
);

@function gradient($colors, $direct: circle at center) {
  
  $out: red;
  
  @for $item from 2 through length($colors) {
    $color: nth($colors, $item);
    $pos-test: #{$item}em;
    $out-string: $color $pos-test;
    $out: append($out, $out-string, comma);

  }
  
  @return blue;
}


@mixin gradient-set ($colors-set: $cold){
  $grad-colors: map-get($colors-set, colors);
  $bg-color: map-get($colors-set, bg-color);
  $size: length($grad-colors);

  //background-image: radial-gradient(circle, gradient($grad-colors));
  background-image: linear-gradient(red, gold);
  background-color: $bg-color;
  background-size: #{$size}em #{$size}em;
  }

HTML, BODY {
  height: 100%;
}

BODY {
  @include gradient-set($warm);
/*  normal, multiply, screen, overlay, darken, lighten, color-dodge, color-burn, hard-light, soft-light, difference, exclusion, hue, saturation, color, luminosity;  */
  //background-blend-mode: multiply, normal;
  }

SassMeister-output.css

source string:6: error: error reading values after colors