title: ggbiplot - change the colour of labels
body: <p>By default, the ggbiplot function gives a graph with loadings as red arrows and unit labels in black:</p>
  
  <pre><code>library(ggbiplot)
  data("USArrests")
  us &lt;- princomp(USArrests)
  ggbiplot(us, labels = rownames(us$scores))
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/e5DXu.jpg" alt="Here"> is the result of that code</p>
  
  <p>How can I change the colour of these labels, and incidentally their size or font?</p>