$colors: (
    yellow: #ffeb3b
);
@each $name, $color in $colors {
    $amount: 40;
    @for $i from 0 through 9 {
        .#{$name}-#{($i*100)} { background-color: lighten($color, $amount) };
        $amount: $amount - 2;
    }
}

$colors: (
    yellow: yellow,
    red: red,
    blue: blue,
    
);
@each $name, $color in $colors {
    @for $i from 0 through 2 {
        .#{$name}-#{($i*100)} { 
          background-color: lighten($color, 10) 
        };
    }
}