> I want to have a sequence of colors corresponding to the the size of circles.
Assuming an n-by-m matrix r should be plotted such that point r(i,j) should appear at x=i, y=j, use meshgrid to create x and y coordinates and then set x, y, and r to bubbleplot as vectors.
The size of the bubbles is defined by |r|and the colors are based r. That way the size of the bubble shows the strength of the correlation and the color shows the direction. That could be switched around, of course.
[x,y] = meshgrid(1:size(r,1), 1:size(r,2));
set(gca,'xtick', 1:size(r,2), ...
'ytick', 1:size(r,1), ...
See comment below to add text labels to each bubble showing the correlation values.