$list: 

(
    theme1: (color: red, background: green, font: (family: Arial, size: 20px)),
    theme2: (color: black, background: white, font: (family: Verdana, size: 30px))

);


$oldList: 
(
    1: (red, blue),
    2: (brown, gold)
);


    @each $index, $row in $oldList
    {
        // $color: map-get($row, color) !global;
        // $background: map-get($row, background) !global;
        // $font: map-get($row, font);

        // $fontFamily: map-get($font, family);


        .theme-#{$index} 
        {
            $c1: nth($row, 1);
            $c2: nth($row, 2);
           // font-family: $fontFamily;
           color: $c1;
           background: $c2;
        }
    }