tk Colors
require 'tk' root = TkRoot.new $canvas = TkCanvas.new(root) { width 360 height 60 } $canvas.pack colors = ['00', '33', '66', '99', 'cc', 'ff'] d = 10 for i in 0..5 for j in 0..5 for k in 0..5 c = '#' + colors[i] + colors[j] + colors[k] x = d*(k + 6*i) y = d*j TkcRectangle.new $canvas, x, y, x+d, y+d, {:fill=>c} end end end Tk.mainloop