ich is what leads to the interleaved appearance where the lines
% overlap, but you can fix that with a bit of restacking:

uistack(h.patch(end:-1:1,2), 'top');

%%
% As an alternative to the opaque bounds with varying colors, you can plot
% the bounds using transparent patches.  When using transparent patches, it
% often makes sense to set the transparency limits to a single value, since
% overlapping patches will automatically show an additive color:

cla
[~,h] = ensemble2bnd(1:52,ice, 'dims', 'xey', 'plot