Simple Sass @for loop to build color classes for gradient text. Generated by SassMeister.com.

_colors.scss

// ----
// Sass (v3.3.0.rc.1)
// ----

@for $i from 1 through 5 {
    .color-#{($i)} {
        color: (adjust-hue(#ff0000,($i*10)));
    }
}

output.css

.color-1 {
  color: #ff2b00;
}

.color-2 {
  color: #ff5500;
}

.color-3 {
  color: #ff8000;
}

.color-4 {
  color: #ffaa00;
}

.color-5 {
  color: #ffd500;
}