- * Returns the sequence feature colour rendered at the given sequence
- * position, or null if none found. The feature of highest render order (i.e.
- * on top) is found, subject to both feature type and feature group being
- * visible, and its colour returned.
+ * Returns the sequence feature colour rendered at the given column position,
+ * or null if none found. The feature of highest render order (i.e. on top) is
+ * found, subject to both feature type and feature group being visible, and
+ * its colour returned. This method is suitable when no feature transparency
+ * applied (only the topmost visible feature colour is rendered).
+ * <p>
+ * Note this method does not check for a gap in the column so would return the
+ * colour for features enclosing a gapped column. Check for gap before calling
+ * if different behaviour is wanted.
+ *
+ * BH 2019.07.30
+ *
+ * Adds a result ArrayList to parameters in order to avoid an unnecessary
+ * construction of that for every pixel checked.
+ *