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


USING: accessors colors.constants kernel math sequences ui
ui.gadgets ui.gadgets.tracks ui.pens.solid ;
IN: rosetta-code.colour-bars-display
 
: colors ( -- ) [
horizontal <track>
{
 COLOR: black
 COLOR: red
 COLOR: green
 COLOR: blue
 COLOR: magenta
 COLOR: cyan
 COLOR: yellow
 COLOR: white
}
[ <solid> gadget new swap >>interior ] map
dup length recip
[ track-add ] curry each
{ 640 480 } >>pref-dim
"bars" open-window
] with-ui ;
MAIN: colors