n>fill <span class="op">=</span> <span class="va">Ii</span><span class="op">)</span>, colour <span class="op">=</span> <span class="st">"black"</span>, linewidth <span class="op">=</span> <span class="fl">0</span><span class="op">)</span> <span class="op">+</span></span>
<span>  <span class="fu"><a href="https://ggplot2.tidyverse.org/reference/scale_gradient.html" class="external-link">scale_fill_gradient2</a></span><span class="op">(</span>low <span class="op">=</span> <span class="st">"blue"</span>, mid <