Task

Display a series of vertical color bars across the width of the display.

The color bars should either use:

   the system palette,   or 
   the sequence of colors: 
   black
   red
   green
   blue
   magenta
   cyan
   yellow
   white


   load 'viewmat'
   size=: 2{.".wd'qm' NB. J6
   size=: getscreenwh_jgtk_ '' NB. J7
   'rgb'viewmat (|.size){. (>.&.(%&160)|.size)$ 20# 256#.255*#:i.8