A somewhat different approach to Walter's to generate the three needed bar handles -- use a 'stacked' plot with the elements on the diagonal, zero for the off-diagonal elements. 'stacked' creates a bar for each row whose heights are each the sums of the elements on the row. (And, need 'stacked' because otherwise passing an array to bar causes it to draw a 'grouped' bar.)
hB=bar(X,diag(Y,0),'stacked');
hLg=legend(TestL,'Location','northwest');
with default color produces
The bars can be customized as desired through the array of bar handles hB.
