JAL-3444 missed commit of removal of object creation test.

diff --combined src/jalview/renderer/seqfeatures/FeatureColourFinder.java
index ee40d83,531a187..57366b9
--- 1/src/jalview/renderer/seqfeatures/FeatureColourFinder.java
--- 2/src/jalview/renderer/seqfeatures/FeatureColourFinder.java
+++ b/src/jalview/renderer/seqfeatures/FeatureColourFinder.java
@@@ -85,6 -85,7 +85,6 @@@ public class FeatureColourFinde
    public Color findFeatureColour(Color defaultColour, SequenceI seq,
            int column)
    {
 -    new Color(defaultColour.getRGB());
      if (noFeaturesDisplayed())
      {
        return defaultColour;
@@@ -99,10 -100,16 +99,16 @@@
      if (featureRenderer.getTransparency() != 1f)
      {
        g = goff;
-       if (defaultColour != null)
+       Color c = (defaultColour == null ? Color.white : defaultColour);
+       if (Platform.isJS())
        {
-         offscreenImage.setRGB(0, 0, defaultColour.getRGB());
+         // Clear the HTML5 canvas color.
+         // otherwise we get a smearing.
+         // For whatever reason, this is necessary BH 2019.10.01.
+         g.setColor(c);
+         g.fillRect(0, 0, 1, 1);
        }
+       offscreenImage.setRGB(0, 0, c.getRGB());
      }
  
      Color c = featureRenderer.findFeatureColour(seq, column + 1, g);