default border color is black

model/src/main/java/lcsb/mapviewer/model/map/species/Element.java

 package lcsb.mapviewer.model.map.species;
 
-import java.awt.*;
+import java.awt.Color;
 import java.awt.geom.Point2D;
 import java.awt.geom.Rectangle2D;
 import java.io.Serializable;
 import java.util.*;
-import java.util.List;
 
 import javax.persistence.*;
 import javax.xml.bind.annotation.XmlTransient;
@@ -159,7 +158,7 @@ public abstract class Element implements BioEntity, Serializable, SbmlArgument {
    * Color of filling.
    */
   @Column(nullable = false)
-  private Color borderColor;
+  private Color borderColor = Color.BLACK;
 
   /**
    * From which level element should be visible.