lass="op">=</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span><span class="st">"blue w/ black outline"</span>, <span class="st">"green w/ yellow outline"</span><span class="op">)</span></span>
<span>  <span class="op">)</span></span></code></pre></div>
<p><img src="introduction_files/figure-html/unnamed-chunk-39-1.png" width="624"></p>
<p>While the previous example won’t win any design awards, more subtle
effects can be helpful.</p>
