%% Display a window containing two color fields.
%% Two 3-element (RGB) column vectors 
%%  with values between 0 and 1
%%  should be passed as arguments.

function showcols(rgb_1,rgb_2)
  cmap = colormap;
  cmap(1,:) = rgb_1';
  cmap(2,:) = rgb_2';
  colormap(cmap);
  image([1,2]);
  line([1.5,1.5], [0.5,1.5],'Color',[0,0,0]);