ue, expensive when genuine but often 
  produced as a mixture of cheaper pigments</li>
  <li>Viridian - deep, transparent cool green, expensive</li>
  <li>Phthalo green - transparent cool green, also very powerful</li>
  <li>Sap green - warm green, often a mixture of pigments</li>
</ul>
<p>The following colors are less intense, and are often referred to as the earth 
tones.</p>
<ul>
  <li>Naples yellow - very light and somewhat dull yellow, sometimes used as a 
  substitute for white</li>
  <li>Y