Generated by SassMeister.com.

SassMeister-input.scss

// ----
// Sass (v3.4.7)
// Compass (v1.0.1)
// ----

$colorslist:
  allcolors (pink, yellow), 
  modules (pink, green), 
  greys (pink, purple, green, yello)
;
  
@each $list, $colors in $colorslist {

@for $color from 1 through length($colors) {
  section.#{nth($list, 1 )} article:nth-of-type(#{nth($color, 1)}) {
    border: 1px solid nth($colors, $color);
  }
}

}

SassMeister-output.css

section.allcolors article:nth-of-type(1) {
  border: 1px solid pink;
}

section.allcolors article:nth-of-type(2) {
  border: 1px solid yellow;
}

section.modules article:nth-of-type(1) {
  border: 1px solid pink;
}

section.modules article:nth-of-type(2) {
  border: 1px solid green;
}

section.greys article:nth-of-type(1) {
  border: 1px solid pink;
}

section.greys article:nth-of-type(2) {
  border: 1px solid purple;
}

section.greys article:nth-of-type(3) {
  border: 1px solid green;
}

section.greys article:nth-of-type(4) {
  border: 1px solid yello;
}