* <p>
* Returns null if
* <ul>
- * <li>feature type is not visible, or</li>
* <li>feature group is not visible, or</li>
* <li>feature values lie outside any colour threshold, or</li>
* <li>feature is excluded by filter conditions</li>
* </ul>
+ * This method does not check feature type visibility.
*
* @param feature
* @return