e fill, with the alpha level of the fill reduced by 50%.</p></li>
<li><p>If full control over fill and line color is desired, the <code>fill_color</code> and <code>line_color</code> attributes can be specified explicitly and will override <code>color</code>.</p></li>
</ul><p>When color is <code>NULL</code> and <code>fill_color</code> or <code>line_color</code> are not specified, the color will be chosen from the theme.</p>
    <h2 class="hasAnchor" id="handling-alpha"><a class="anchor" href="#handling-alpha