BorderPainter setColor() overwritten by setLookAndFeel()

[HelmsDave]

This issue is apparent in EmptyPlotExample, BorderPainter is created and the color is set with setColor( float[] rgba ), yet the requested color is not used.

As it happens, BorderPainter.setColor( float r, float g, float b, float a ) works, but BorderPainter.setColor( float[] rgba ) does not work.

BorderPainter.setColor( float[] rgba ) should be modified to add: colorSet = true;