title: How to generate a legend with colors in PlantUML?
body: <p>I want to color classes in my class diagram, based on a certain criteria, and then display a legend, that would look roughly like:</p>
  
  <p><img src="https://i.stack.imgur.com/x2ixw.png" alt="Legend with colors"></p>
  
  <p>If I could add an HTML table within PlantUML's <code>legend</code> and <code>endlegend</code>, I could achieve this by changing the cell backgrounds. However, adding the HTML <code>&lt;table&gt;</code> doesn't work. I also tried using <a href="http://plantuml.sourceforge.net/salt.html" rel="noreferrer">PlantUML's <code>salt</code></a> to insert a table, but I couldn't find any way to color the cells of the table.</p>
  
  <p>Is there any way to achieve this?</p>