title: How do I set color hues for a grouped line chart?
body: <p>I'd like to set the colors for my ggplot line chart from dark blue to light purple.</p>
  <p>I think I might have to use color brewer but I'm not sure the right way to do it</p>
  <p>Can I set the high color to some color and the low color to some other color?</p>
  <pre><code>iris %&gt;% 
    ggplot(aes(Sepal.Length, Sepal.Width, group = Species)) +
    geom_line()
  </code></pre>