Generated by SassMeister.com.

SassMeister-input.scss

// ----
// libsass (v3.3.2)
// ----

.ratings {

  @for $i from 0 through 4 {
      &--#{$i} & {
  
  		&__item:nth-of-type(n+#{$i+1}){
  			background-color: colour(grey, middle-grey);
  		}
  	}
  }
}

SassMeister-output.css

.ratings--0 .ratings__item:nth-of-type(n+1) {
  background-color: colour(grey, middle-grey);
}

.ratings--1 .ratings__item:nth-of-type(n+2) {
  background-color: colour(grey, middle-grey);
}

.ratings--2 .ratings__item:nth-of-type(n+3) {
  background-color: colour(grey, middle-grey);
}

.ratings--3 .ratings__item:nth-of-type(n+4) {
  background-color: colour(grey, middle-grey);
}

.ratings--4 .ratings__item:nth-of-type(n+5) {
  background-color: colour(grey, middle-grey);
}