span class="op">=</span> <span class="st">"white"</span>, high <span class="op">=</span> <span class="st">"red"</span>, midpoint <span class="op">=</span> <span class="fl">0</span>, </span>
<span>                       space <span class="op">=</span> <span class="st">"Lab"</span>, na.value <span class="op">=</span> <span class="st">"grey50"</span>, </span>
<span>                       guide <span class="op">=</span> <span class="st">"colourbar"</span>, aesthetics <span class="op">=</span> <span class="st">"